Percussive Maintenance



""...and then you smash it with a hammer!""

- Eddie Izzard

''Tapping the car with a hammer: $0.00. Knowing where to hit it: $5,000.00.''

Bringing a malfunctioning piece of equipment back on-line by giving it a good bash.

Also known as "Technical Tap", "Ape Mechanics," "Fonzarelli Fix", "Spike Spiegel School Of Repair", or "Emergency Repair Procedure #1." This is a case of Truth in Television, as many people will often do this with malfunctioning machinery—with mixed results. In real life, it works best (where it works at all) when dealing with machines with moving parts capable of being physically jammed or temporarily impeded (gears or switches), hydraulic systems suffering particular kinds of plugs or clogs (fuel lines or sump pumps), or internal components whose function depends on precise alignment and which have become misaligned somehow (vacuum tubes, early transistors, and connection interfaces) -- all hallmarks of pulp-era storytelling where technology was still a hands-on art. Realistically, it is almost impossible to work with modern delicate electronics or futuristic solid-state circuitry/machinery (cf. Drake's camera-bash from Aliens, below), but the appeal of a highly emotive and easy-to-show repair technique often wins out over boring technical accuracy.

In other words, Don't Try This At Home. Repeatedly whacking your DVD player is highly unlikely to make the picture any clearer, although it may still make you feel better. Soon-to-be-extinct exception: CRT screens (apply fist to casing, not glass).

It could be argued that this might be a rare example of both Truth in Television and Reality Is Unrealistic. Might be justified if the character uses Machine Empathy to determine where to strike.

A common variation involves a character, having tried every method they can think of to get something to work and after working for hours with no success, hits the malfunctioning device solely for the purpose of Percussive Therapy, only for the device to respond to the Percussive Maintenance and start working again.

Compare Percussive Therapy where a character does this solely for their own emotional benefit, rather than the proper functioning of whatever they're hitting. For use on life forms, see the Dope Slap, Get a Hold of Yourself, Man!, Spank the Cutie or Don't Make Me Take My Belt Off.

Advertising

 * This advertisement features a man running through a delightfully old-fashioned area (Kastelruth/Castelrotto, Italy) in order to fix a delightful old-fashioned mechanical clock as the townspeople wait. Unable to find fault with the machine, he attempts Percussive Maintenance in desperation (perhaps by accident), and the clock strikes three, allowing everyone to perform their scheduled activities on time.
 * A recent ESPN ad features Landon Donovan with an acting-up copier. He kicks the copier...and it produces a yellow card. When he complains, it produces a red card!
 * A promo for a GSN programming block called "Sunday Night Buzz" featured a woman in an office panicking over a malfunctioning copier. "It keeps jamming, what are we going to do?!" Cue a sarcastic man who suggests "Kick it?! (hits buzzer) We'll kick it!"

Anime and Manga

 * Digimon Adventure: Taichi did this a lot.
 * Used with some success in the fifth episode when Taichi rescues Andromon from under a pile of gears by kicking the gears.
 * Also attempted in the sixth episode, where Koushiro's computer is acting up. Typically, both Taichi and Agumon say that all it needs is a good whack and charge at Koushiro, who then moves out of the way causing Taichi and Agumon to Cross Counter one another.
 * Subverted nicely in Our WarGame, where Taichi hits his father's computer (the monitor, not the main system) when WarGreymon and MetalGarurumon on the internet slow down. The computer promptly does a BSOD... completely paralysing their Digimon.
 * Spike Spiegel of Cowboy Bebop, from whom comes one of the alternate names of the trope, claims, "My ship works better when I kick it." His attempt to fix an antique Betamax player in the same fashion, however, does not turn out so well.
 * Higurashi no Naku Koro ni
 * Rena "fixes" a sulking Mion the same way, saying it's how she fixes her TV.
 * A more serious example occurs at the end of Meakashi-hen. Whereas seems to gain some grip on everything that had happened as she fell, in the game, she hit a roof and landed there, and that was what allowed her to overcome her insanity....
 * Another serious example is in Tsumihoroboshi-hen, when Rena takes the class hostage and started "fixing" Mion... while holding her cleaver.
 * A semi-serious example of either this or Dope Slap occurs in the manga version of Tatarigoroshi-hen, where Mion smacks Rena in the back of the head to get her out of one of her dark moods and/or get her to shut up about Oyashiro-sama's curse.
 * This is part of the reason why the Lupin III crew keeps Goemon around.
 * In the Mahoraba manga, Megumi tries to fix a gas stove like this, calling it the "Russian Repair Method", possibly as a Shout-Out to Armageddon. It blows up (comedically) in her face.
 * One episode of Martian Successor Nadesico sees Ruri repair a malfunctioning Jovian communication device by walking up, saying, "Kick," and giving it a swift boot to the side. Particularly hilarious since this happens right after the resident Gadgeteer Genius has declared that he has no idea how to fix something as crazily advanced as a Subspace Ansible.
 * In Darker than Black, Hei apparently fixes his landlady's TV by hitting it with his hand. This is our first hint at what Hei is capable of.
 * In Doraemon, this is the preferred method of television repair because Nobita's family is so poor (Nobita's mother even shows Doraemon the preferred angle at which to whack) until Doraemon uses a magic cloth to restore the television to shiny newness.
 * Sola: Matsuri Shihou does this.
 * In JoJo's Bizarre Adventure, Jotaro kicks a scooter to start it up.
 * In one Super Robot Wars manga, a character suggests "fixing" Tifa Adil's Demonic Possession problem with this. Garrod, obviously, isn't too happy at the start.
 * During Mihoshi's introduction in Tenchi Muyo, she stomps her foot to correct her cruiser when it starts acting up. It actually makes her look pretty cool before the rest of the episode establishes her as a complete bubblehead.
 * In Zone of the Enders: Dolores, I, the title character, a Humongous Mecha Robot Girl, applies this to herself when she inexplicably throws a jealous fit after James recovers a female enemy pilot.
 * Subverted in one episode of Yumeiro Patissiere. Ichigo tries to fix a oven by karate-chopping it. The oven starts functioning... but explodes in less than fifteen seconds.
 * In the second season of Mobile Suit Gundam 00 the members of Celestial Being try to get the titular Gundam's Twin Drive system to work, but never seem to get it to stable operation, even with the hypothesized 'best combination' of  GN Drives. Guess how  gets it to work when the mothership gets attacked a few minutes later.
 * Used by Tamama in an episode of Keroro Gunsou, where he fixes a machine with a rapid fire punch attack. It does take a few tries to find the attack that works, though.
 * The whole premise of Hikkatsu is centered on this, where geomagnetic abnormalities have let to a complete technological breakdown, with various electronics, vehicles and appliances going berserk, and after his martial arts master is killed by a runaway construction vehicle, the main character tries to turn Percussive Maintenance into a martial art.
 * Lucky Star: When a CRT television goes on the fritz, Miyuki mentions having heard of cases where banging on it helped. Konata, having heard of that too, tries it, and it works. When Hiyori tries it later on her frozen desktop computer, however, it goes completely dead.
 * In A Certain Magical Index, Touma meets Mikoto for what he thinks is the first time when he just lost ¥2000 (roughly $20) to a soft drink vending machine. She gets a beverage from the machine by kicking the it (as seen on our Modesty Shorts page), and explains that the mechanics have rusted due to age. Then, to regain his lost money, she hacks the machine, bombarding them with cans and setting off the alarm.
 * A Certain Scientific Railgun shows that this wasn't the first time she's kicked that particular machine to get it to dispense a beverage.
 * Tower of God features a little scene between Hwa Ryun and Koon, where Hwa gets juice out of a disperser he was having problems with by hitting it. She comments on how he didn't read enough manhwa and he tries to follow her suit. He hurts his hand.

Comic Books
"Deadpool: Once, my TV didn't work, so I kicked it. And it started working again."
 * Tech support according to Deadpool.

""All those years of school to learn where to hit it with a hammer.""
 * Elf Quest: The Rebels #3 page 19 and 20.


 * There was a Star Wars Expanded Universe comic where a frustrated and angsty Anakin Skywalker (is there any other kind?) fixed a small cleaning droid but it still wouldn't work, even when he took it apart and reassembled it. Enter Aayla Secura to give it a thump, getting it to activate, and tell him that he shouldn't ignore the simple things.
 * In a |The Transformers comic, a two-bit crook finds Megatron, whose cyboneural circuits have been knocked loose in an earlier issue. The result is that Megatron has no free will, and will simply do whatever anyone else tells him. The crook embarks on a crime spree, but when he goes to confront his old boss, he drops Megatron—conveniently reconnecting his circuits, allowing him to Take Over the World once again.

Comic Strips

 * A 1970s comic strip titled Campus Clatter included one incident where the college's new computer was malfunctioning. The genius student and a professor discussed possible high-tech fixes, but an ordinary guy suggested it needed "a good swift kick!" and applied one. The computer began running perfectly—and printed out the words, "Thanks, I needed that!"
 * In a 1960s installment of Our Boarding House, Major Hoople successfully repairs his old TV by using "the BSKK method: Bang, Slam, Kick, Kick."
 * One Peanuts arc had Snoopy demonstrating that he could make himself invisible except for his grin, just like the Cheshire Cat. Then something went wrong and he couldn't become visible again. Hearing what'd happened, Lucy suggested, "Maybe he's just lost his picture." Then she slapped Snoopy the way, she said, her dad hit the TV whenever the picture was on the fritz. It worked. Walking away, Lucy remarked this would work out fine, because her fee for TV repair was higher than her fee for psychiatry.

Fanfiction
"She enjoyed the car when it was working, but the invisibility booster had gone out for a good thirty minutes before either of them had noticed. A well-placed kick from Harry had started it up again; 'percussive maintenance' he called it."
 * Lampshaded in the Harry Potter fic Growing Up Kneazle, where Harry and Ginny fly the enchanted Ford Anglia second year instead of Harry and Ron:

Films -- Animation

 * Atlantis the Lost Empire: Milo uses this method, in the form of an elaborate series of blows, to fix both the boiler at the Smithsonian and Mole's digging machine.
 * At the beginning of Up, Carl is going downstairs on his Stair Lift, when it stops halfway down. One fistbump later, it's going again.
 * In A Goofy Movie, Max and Goofy are visiting an incredibly lame opossum-centered Theme Park. The Chuck-e-Cheese-ish animatronic band gets stuck at one point (repeating the same phrase over and over like a stuck record), until an employee whacks the base with an elbow. All better.
 * Happens in Toy Story 3: Apparently the best way to get your Buzz Lightyear back to normal after a hard reset is to

Films -- Live-Action
"Capt. Colin Maud: (walking up to a stalled vehicle) My old grandmother used to say anything mechanical, give it a good bashing. (hits hood with his swagger stick) Capt. Colin Maud: Try it now. (vehicle cranks) Private Flanagan: Sure, now; that did it."
 * Used by Peter Ustinov's character Jules in We're No Angels (1955). He opens a lockbox by meditating, then tapping it with the edge of his hand. So this may be Older Than They Think.
 * The Longest Day:

"Drake: Only works if you bash the right side. Hudson: What happens if you bash the left side? Drake: Your head implodes.
 * Star Wars
 * Han Solo used this method to fix a sputtering Millennium Falcon, in The Empire Strikes Back. Given the general state of the ship and Han's personality, it's a minor miracle that he only does this once.
 * In the Expanded Universe, he does it often enough that he and Lando (the Falcon's previous owner and one of Han's best friends) refer to it as "Emergency Repair Procedure Number One".
 * A Shout-Out to Han's repair method is given in the film Fanboys.
 * Used in Aliens by head-smacking: "Drake, check your camera... [bash] that's better".
 * The novelisation expands this scene. Drake mentions that he learned that in training:
 * Cue at least one marine trying to bash Hudson's helmet on the left side."

""This is how we fix problem in the Russian space station!" "Components. American components, Russian Components, ALL MADE IN TAIWAN!""
 * Done in Armageddon, when the crew was stranded on an asteroid: The Russian cosmonaut fixed the ship by banging the engines with a wrench, possibly in a Shout-Out to Star Wars

"Matrix: Come on you piece of shit, fly or die! (seaplane starts) Works every time."
 * Wolff, the Solo-wannabe from Spacehunter: Adventures in the Forbidden Zone, calls this "Emergency Repair Procedure #1".
 * Back to The Future
 * At the climax of the first movie, Marty can't get the DeLorean started until he despairingly hits his head against the steering wheel, at which point the car and its equipment spontaneously roar to life.
 * Averted at the beginning of the movie, when Marty smacks the time circuits and they stay dead. Played straight in Part II, when Doc hits the time circuits to stop them from glitching.
 * Ace Ventura also had to do this while his problematic car was under attack by an angry man.
 * The title character of Judge Dredd used this to get a Mark 4 Lawmaster (flying motorcycle) to work.
 * Double Subverted in Golden Eye 1997. After the car of the CIA agent transporting James Bond breaks, said agent tinkers with it, finally asking Bond for a hammer ("No, [not that one,] the sledge.") He leans over and lightly taps the engine with the gigantic hammer, then steps back and swings it full strength, making it run again. Joe Don Baker doesn't do subtlety.
 * The Julie Andrews Movie Musical Thoroughly Modern Millie (as well as the The Musical adaptation for the stage) featured an old timey elevator that you had to tap-dance in to get started.
 * Hudson Hawk. While Eddie is climbing on top of the Vatican he jostles a television aerial causing the Pope's TV set to have wavy lines. The Pope tries to get the set working by hitting it with his staff.
 * At one point in Fast Times at Ridgemont High, a locker is opened by hitting it just right.
 * The ship's boiler in The African Queen has to be kicked vigorously every morning to get started. Charlie explains that this is caused by a screwdriver stuck inside. He admits he could open the panel and remove it, but he leaves it in there because kicking it is kind of fun.
 * In Commando, Cindy couldn't get the seaplane to start. Then John Matrix pounds the control panel.


 * In Iron Eagle, Charles "Chappy" Sinclair turns his jukebox on by kicking it, and off by slapping it.
 * In the Jackie Chan film First Strike, Jackie has to spend a night on the street and ends up in a window alcove on an apartment building. The homeless man in the next alcove advises him that hitting the wall hard enough will turn off the building's lights.
 * At one point in Flight of the Intruder, the navigation computer in the protagonists' A-6 Intruder attack jet flakes out. Tiger Cole claims that the manual says to "kick the damn thing" to get it to start again. Justified in that the likely cause for that computer to fail is for the internal gyroscopes to get stuck, with the kick knocking them loose again.
 * In the made-for-TV film Babylon 5: Legend of the Rangers, the crew is trying to get an old Minbari ship ready for launch. The Captain (a human) suggests his Number Two and best friend (a Minbari) smack the console to get it working. The Minbari replies that this is barbaric and not a way to work with sensitive technology. Later, frustrated at being unable to get a screen working, he hits the console, and it immediately starts.
 * Towards the end of Tron: Legacy,
 * Referenced in Minority Report. When John has Precog Agatha hooked up to a recording device to see her visions and sees one he saw before, he tells the techie he's shanghaied into helping him to "slow it down." He responds by asking, "Slow it down? What do you want me to do, whack her in the head?"
 * In Splash, when Tom Hanks gets stranded on the boat, it doesn't start until he opens the casing and whacks it with a hammer. At which point it promptly fires up, lunges forward, and pitches him overboard.
 * At the beginning of Jack Frost 1998 (the family version, not the serial killer version), Michael Keaton's character is going to a music gig with his band but then decides to go back to watch his son's hockey game. His best friend gives him his car. A snow stom starts, and the guy is trying to see where he is going. Then the windshield wipers stop working. This is when he tries Percussive Maintenance on the dash to try to get them working again, as his friend showed him before. Unfortunately,.
 * And You Thought Your Parents Were Weird: Max gives the robot Newman a whack on the head to fix a voice glitch.
 * Red Planet: "No joy on all scenarios for engine ignition. That includes hitting the console."
 * Transformers: Dark of the Moon: When Sam's car (not Bumblebee but some old "sad piece of shit") won't start, angry as he already is, his best resource is to open the hood and start kicking the engine frantically. It's a mix of this and Percussive Therapy.
 * In the opening of WarGames one of the Air Force launch officers reports a warhead alarm on one of the missiles. The other officer tells him, "Tap it with your finger". He then taps the indicator light and it goes out, showing that the warhead was fine, it was just the alarm light was seated incorrectly.

Jokes

 * Old joke: A man can't get his car working, so he gets it into a repair shop. The repairmen turns over the engine a few times, then goes to his tool rack and grabs a hammer. He comes back, pops the hood, gives the engine one quick rap with the hammer, then turns the key and—presto! Engine works. The repairman then hands the owner his bill for $220, to which the owner responds "What!? $220 for hitting it once with a hammer?" The repairman responds, "Nope, hitting with the hammer is only $20. The other $200 is for knowing where to hit it."

Literature

 * In Larry Niven's Ringworld, Teela Brown activates her sky-cycle's emergency booster at a key moment by fainting and smashing her face on the control panel, thus saving her life. The emergency booster required several controls to be hit in a specific order, at least one of which was recessed and thus much harder to hit accidentally. The other characters take this as proof that she was literally Born Lucky (a plot point in the story).
 * In Tom Holt's Odds and Gods, Thor managed to get a flying engine to work again merely by threatening to hit it with a hammer, which shows that even non-sentient machines know when to stop mucking about.
 * Virgil Cole, a U.S. Navy bombardier in Stephen Coonts' Flight of the Intruder, uses the Fix to keep his A6 bomber's balky primitive computer in line.
 * Lampshaded in Good Omens, in which one of the Bikers of the Apocalypse takes up the name "Things That Don't Work Even After You've Given Them A Good Thumping".
 * Terry Pratchett again in the Discworld novel Hogfather, where Archchancellor Ridcully asks if the term "Reboot" means to kick the computer. Ridcully also gets surprisingly good results by threatening to hit HEX if it doesn't start doing what it's told.
 * The short story At the Rialto by Connie Willis involves a group of Quantum Physicists at a convention. An overhead projector isn't working and one scientist explains that "it needs its fractal basin boundaries adjusted". She proceeds to whack it twice and it works.
 * Robert Heinlein was an old-school engineer; he loved this trope.
 * In The Cat Who Walks Through walls, the protagonists manage to rent a car from a very, very low cost rental agency and proceed to fly to the moon (they were already in space and the car's a spaceship). Being a budget rental, everything goes wrong as they try to land. At one point the computer (which controls the rockets) fails. The husband hits it. No go. He hits it again. No go. His wife hits it nearly hard enough to crack the casing. It comes back on. (Briefly.)
 * In the short story "The Long Watch", Lieutenant Ezra Dalquist fixes the Space Patrol with a hammer. That is, the Colonels are planning a coup; they plan to use the Patrol's nuclear bombs not to stop wars (the mission of the Patrol), but to rule the world and want Dalquist on their side. He agrees, then walks out, tricks his way into the facility where the bombs are stored, sets up a deadman switch so that they can't blast their way in after him, and takes a hammer to the delicate instruments in the bombs. He realizes that's not enough and takes the hammer to their plutonium cores. Problem fixed, trope inverted.
 * Julio Poertena from the Prince Roger-series carries a big wrench which he uses to adjust the attitude of malfunctioning gear. The twist is that the "wrench trick" is actually better than the standard procedure for removing jammed powered armor.

Live-Action TV
""Behave!" *WHAM!*"
 * The Fonz (pictured) on Happy Days, using this trope to get the jukebox to play free songs and as a way to fix some cars. This was, of course, to show how The Fonz could channel Rule of Cool like magic. To the point where he knew how and where to strike the jukebox to play whatever song he wanted.
 * Lampshaded in one episode where he hits the brick wall of a building to turn the exterior light off. Ron Howard's character is stunned near-speechless, to which the Fonz simply explains, "It's a gift."
 * The famed jukebox scene was subverted in an episode of Cheers when Cliff tried to fix the bar's broken jukebox by kicking it. It obviously didn't work.
 * Also used many times by the Doctor in Doctor Who, often on the TARDIS controls. Some notable instances:
 * In "The Three Doctors", the Second Doctor fixes a radio by whacking it against the TARDIS console.
 * In "State of Decay", the Doctor thumps a malfunctioning scanner in the rebels' base, and it starts working properly again. "Aha! Earth technology!" he remarks.
 * Toward the end of the 1996 telemovie, the Doctor uses the Fix on the TARDIS.
 * The current incarnation of the TARDIS actually has a hammer attached to the console with a chain for on-the-fly percussive maintenance.

""Did that work?" (defensively) "Yes!" "Did it hurt?" "Yes...""
 * At one point in the new series, the Doctor attempts to kick the TARDIS back into working order. The exchange goes something like this:

"Troy: I'm kinda tired of this song. (smacks the jukebox, but nothing happens) I would have expected sex, had that worked. Veronica: Had that worked, you would've gotten it."
 * Of course, the TARDIS is alive, so this might be a combination of Machine Empathy and Time-Lord technology.
 * The robot Kryten on Red Dwarf was known to do this to himself on occasion.
 * In the Get Smart episode "Schwartz's Island", Siegfried does this to the secret technobable machine by kicking it.
 * When the crew of Babylon 5 finds on old Earth ship in the Season 2 ep "The Long Dark," Ivanova smacks a control panel to get the ship's systems running.
 * In the Small Wonder pilot episode, Jamie fixes a malfunctioning Vicki by slapping her, remarking that it's how Ted fixes the stereo. In the third-season episode "Bank Hostages", Vicki herself performs this on an errant ATM: "That's how my father fixes me."
 * Hogan's Heroes: "It's a German machine -- all it understands is force!"
 * In the pilot episode of Star Trek: Deep Space Nine, O'Brien, trying to transport Odo back after a bit of sabotage on the Cardassian ship, is frustrated with the transporter not working. He kicks it—and Odo promptly materializes on the pad. It was the pilot and the Cardassians had left the station in a MESS. They were lucky that the transporter was even working. The novelization of the episode takes it a little further—his foot actually hit the control he was missing on the unfamiliar control panel.
 * Lampshaded in a first season episode of Veronica Mars:

"Carter: Smack it. Stark: Seriously?"
 * Lampshaded in Stargate SG-1. While trying to frantically repair the Odyssey before the ship comes under fire, Vala rams a power crystal into one of the slots despite the fact that it's not supposed to fit there. Vala then remarks that that almost never works.
 * The second-season premiere of Dollhouse features a more futuristic version of this when Paul Ballard, trying to save Echo from capture by arms dealer Martin Klar, repeatedly punches the Active, hoping to coax out a personality that can defend itself. He eventually brings out the same fighter imprint that tried to ambush him in the previous season, and Echo manages to turn the tables on Martin and subdue him.
 * Daisy and Onslow operate their TV this way on Keeping Up Appearances, even thumping it in certain spots to bring in the right channels.
 * Scrubs
 * Elliott's sorority sister hits a Jukebox and after it turn on, she says "Hey, I'm the Fonz!"
 * There was also an Imagine Spot in which J.D. fantasized about being the Fonz, and performing Percussive Maintenance on a patient in a coma.
 * The Todd claims that he saved a dying patient by giving him a high five. "The Miracle Five!" Dr. Cox replies, "Great story. It begins with a fundamental lack of understanding about the human body and ends with you shattering some old guy's hand."
 * Eureka
 * The episode "Best in Faux", when Stark tells Carter the computer is malfunctioning:

"Rosso: You think you're pretty cool, don't you, Daniel? Desario: No, I don't think I'm cool. Rosso: You don't think you're the Fonz or something? If a jukebox was broken, do you think you could hit it and it would start playing?"
 * Also the episode "Dr. Nobel".
 * This is how Al fixes Ziggy's handlink in Quantum Leap, so often it's practically a Character Tic. Although it sometimes does more bad than good. In the third-season episode "The Great Spontini", he actually manages to break the handlink, and is seen with a different model from that point forward.
 * In Bottom, episode "Contest", Richie tries to fix some dodgy TV reception by waving his palm above the set and giving it a sharp smack, causing it to go off completely. Eddie quickly gets up and successfully fixes it with another smack. Richie, impressed, smacks it again causing the television to explode, throwing him to the floor.
 * On The Sopranos, Paulie Walnuts deals with a recalcitrant DVD player with what his Army Signal Corps training referred to as a 'brogan adjustment'. It works about as well as you'd expect a Paulie Walnuts plan to work.
 * Referenced on Freaks and Geeks: Mr. Rosso catches Daniel Desario trying to set off the school fire alarm in the hallway:

"H.G. Wells: Back in the old days when things didn't work..."
 * Lost
 * In the episode "Namaste", Miles uses Percussive Maintenance on the Dharma security monitors.
 * And in a later episode, a character slaps around an atomic bomb in order to get it to explode. This is presented as a good thing.
 * The Sarah Connor Chronicles
 * A car bomb resets Cameron back to killer mode. After chasing John and Sarah across the city, she winds up slammed between two trucks and pleads with John not to deactivate her because she's "fixed now". Of course, it's slightly more complicated than that... (It should be noted that there's a high possibility that she was lying when she said that she was fixed.)
 * In another episode, when John tries to buy some "Let's" brand chips from a vending machine, it gets stuck. Cameron hits the machine in just the right spot to make it dispense several products at once and give John his money back.
 * NCIS
 * This is Gibbs' favorite method of fixing technology. Subverted in that he has broken a truly alarming number of computers and cell phones. Lampshaded when he gives his phone to Kate to fix and she merely drops it in the trash and replaces it with an identical phone from the stash she keeps in a desk drawer.
 * This is also his favored method of fixing subordinates.
 * Tony DiNozzo in a later episode is shown to use this method to score free candy from the machines in the break room.
 * Ziva is seen doing this as well. Unlike Tony, she is actually applying this to a vending machine in a hospital where she has spent most of the episode. Upon seeing her do it, Tony remarks something along the lines of "you know you've been somewhere too long when you know how the machines work".
 * Jeremy Clarkson's general attitude to car maintenance on Top Gear.
 * During the Top Gear Ground Force special, May and Hammond assumed that Clarkson was going to use a hammer to get rid of weeds, since that's what he normally uses for fixing everything. He didn't. He got a shotgun instead.
 * Farscape
 * One episode features a particularly dodgy ship that only really works when the engines are thumped with a stick.
 * A variation of this occurs when Aeryn awakens Pilot (one of the many organic components of a Living Ship) from a coma by pumping him with adrenaline and kicking him. With both feet.
 * If a Luxan is bleeding and the colour is inky-black, Percussive Maintenance must be performed on the wound until the blood turns to a clear colour. Yes, an entire species whose first aid procedure consists of Percussive Maintenance. It's that kind of show.
 * An episode of the Disney sitcom Hannah Montana has one of the characters, Oliver, have the nickname "Locker Man" because he is gifted with the talent of being able to open a stuck locker with a series of blows.
 * Lexx's indestructible assassin Kai finally suffers serious damage -- which he calls being "out of alignment" -- when he jumps down to a planet from a spaceship in orbit. The solution? Make another jump and land on his other side. It takes a couple of tries, but it works.
 * Warehouse 13
 * Claudia uses this method in one episode, and mentions it by name, in order to get the holographic display projector to work properly.
 * Artie also resorts to this method whenever his computer decides not to cooperate.
 * When the time machine breaks, this is the method they use to repair it.

"Thelma: Percussive maintenance. Works every time!"
 * Referenced directly by name on Space Cases -- Thelma kicks the engine, which has been making odd noises, and it resumes its more usual hum.


 * Referenced again by name by Chloe on the eight season of Twenty Four.
 * Mr. Bean attempted to use Percussive Maintenance in the episode "Mind The Baby, Mr. Bean" to cheat at one of those token pusher machines. It didn't end well:
 * Power Rangers
 * In the second episode of Power Rangers RPM, Dillon and Ziggy notice a bunch of Grinders setting up a weapon to attack the Yellow Ranger's zord. Dillon tries to start his car, but can't because it's out of fuel. A hard whack on the steering wheel later and he gets it going again, running on the fumes.
 * That's nothing. In Power Rangers Samurai, the method for clearing jams in the Lightzord's disk launcher system is to smack the Lightzord in the butt.
 * Power Rangers Zeo had a visiting Cestro (Blue, The Smart Guy, basically the Alien Rangers' Expy of Billy and so often working alongside Billy. Like Billy, his solutions usually involve lots of techie-sounding made-up words.) make something in the command center work by banging his fist on it, causing a shower of sparks to erupt. He says "there, it's fixed!" It works.
 * Bob Barker was fond of kicking and/or slapping stuck set pieces on The Price Is Right. The pricing game Squeeze Play was the most common victim.
 * On Saved by the Bell, AC Slater could use this to make lockers open.
 * In one episode of MacGyver, starting a car this way becomes a Running Gag.
 * Parodied on Brass Eye, where viewers were advised by unwitting celebrity guests to bang on electricity wires with large hammers to stop the north of Britain from being catapulted into Finland.

Music Videos

 * In the beginning of the clip for "Derezzed", one of the Daft Punk kicks the Derezzed video game cabinet to make it start.

Puppet Shows

 * On an early episode of Sesame Street, a Dalek-like robot named S.A.M. arrives on Sesame Street (he meant to go to Mulberry Street), asserting repeatedly that "machines never make mistakes; machines are perfect -- are perfect -- are perfect." The humans have to thump him hard to make him stop repeating the phrase, for which he thanks them.

Tabletop Games

 * In Time Lord, a Doctor Who tie-in RPG released in the 1990s, it was possible to equip characters with this ability (called "Bench-Thumping" in the game).
 * In Rifts, this is an ability of some of the mystically-endowed-mechanic-type classes, like Techno Wizards and Operators, under the punny name "Guerrilla Repairs".
 * In the Old World of Darkness game Changeling: The Dreaming, Nockers had the ability to fix machines by smacking and/or threatening them.
 * Warhammer 40,000 gave us the (in)famous "Ritual Slap on the Left".
 * And because of the peculiar nature of Ork technology, this method is the normal means of fixing most broken (or in many cases, perfectly functional) Ork machines.
 * Dark Heresy has it as a talent to unjam weapons. The Technical Knock is a swift prayer to the Omnissiah, and a swift smack to the jammed weapon. And it always works.
 * Also, there's "Rite of Ignition" talent for Lathesmaster (character option for non- Tech Priest workers from Forge Worlds) allows to use Strength instead of Intelligence for Tech-Use skill when starting machinery.
 * In GURPS 4e if cinematic rules are in effect and the GM allows, it is possible to do this at a big penalty if the kicker is sufficiently skilled.
 * In Iron Kingdoms d20 setting, the Bodger class has this as one of their main class features. At higher levels, they can even do this at range ("Toss a Hammer At It").
 * In Spycraft 2.0, the Wheelman class gains the "Manual Adjustment" ability, letting them use this, depending on their level, to automatically succeed at most Mechanics, Electronics, and Security skill checks, should the initial skill roll fail.
 * Iron Crown Enterprise's Cyberspace. One entry in the Equipment Mishandling Chart said "A sharp slap and the item begins to function normally again."
 * The D20 system also gives us the "Guerilla Repair" ability, which allows the user to keep a malfunctioning weapon firing a few turns yet through anything from this trope to verbally reprimanding it.
 * Starblazer Adventures, based on the 1980's British science fiction Comic Book.
 * The "Thump of Restoration" stunt (under Engineering) and an Engineering roll will cause any device that isn't working to start working again. However the device only works for a limited period of time: the better your roll, the longer it works.
 * The "Just Hit It" stunt works exactly the same way, but specifically for starship engineering.

Video Games
"Maintenance Droid: I always say, there's no repair quite like hitting something."
 * Team Fortress 2
 * The Engineer fixes and upgrades his machines by hitting them with his wrench. Just as good: If you hit an enemy or enemy machine with this wrench? Head trauma or a damaged building respectively.
 * The game's (fanmade) "manual" [PDF] (as accessed online) is actually a manual on the Sentry, an automatic gun. The directions included for upgrading and setting up a sentry are all elaborate cover-ups of "hit it with your wrench".
 * Even better: In the game's predecessor, The Medic can heal teammateswith his axe.
 * Similarly, the Engineer could heal teammates' armor by hitting them with his wrench.
 * Made even better with the Gunslinger. A robotic hand added as an alternative to the wrench in the new engineer update, it lets you repair your buildings by punching them.
 * The Battlefield series toys with this trope somewhat.
 * The Engineer in each game in the series is usually equipped with some kind of tool or device that allows them to repair vehicles as long as said tool is in contact with said vehicle.
 * Battlefield: Bad Company has a Drill. Yes, you drill health into tanks and jeeps. As long as you know the drill. (It's really more of a battery-powered socket drill, but that doesn't change the fact that you repair things by grinding them with the drill)
 * Devil May Cry
 * Devil May Cry 3 features Percussive Maintenance in its most basic form, with Dante punching a jukebox to get it to play ("This party is gettin' crazy!"). Destroying a jukebox in Mission 3 will inexplicably incite it to play a few notes (a remix of the combat theme from DMC 1).
 * Also from DMC 3's fifth mission, when Dante used an ornate trident to trigger a switch. It didn't work. Guess what he did? He.
 * Similarly, in Devil May Cry 4, Nero finds that the controls for lowering a drawbridge refuse to operate. He walks away in frustration... and then whirls around and shoots the uncooperative console. It sparks and then explodes, after which the red light turns to green and the drawbridge lowers (It should probably be noted that he looked pretty surprised when this happened, suggesting that the shooting of the controls wasn't deliberate Percussive Maintenance so much as him venting the aformentioned frustration). Dante once gets into trouble hitting the jukebox; he hit it a little too hard, as he punched it with enough force that the metal on the jukebox bent inwards from the impact, leaving his fist in a crater that he just made.
 * Inverted in Wing Commander IV, during the cutscene where Pliers (ship's mechanic) has found a disc of unknown purpose in a captured Dragon (to the characters, that is—the players know it as a Flash-pak, a bomb capable of burning out a entire capital ship if it hits ANYWHERE on the hull). He doesn't know what it is, so he drops it on the deck, while everyone around him dives for cover—when it doesn't explode, he then picks it up, states that that's apparently not how it works, and resigns himself to some actual work.
 * An FMV cutscene during a mission of the second Crusader game has Denning doing this, with the upgrade of the power outage apparently affecting the entire base.
 * In one scene in Army of Two, either Salem or Rios is trying to get into a room containing a circuit breaker needed to activate a monorail. When trying to flick the switch to open the breaker room, it doesn't work, even with a few hammer blows from the contractor's fist. It isn't until he headbutts the switchbox that the door opens.
 * Final Fantasy
 * In Final Fantasy X, Tidus hits a piece of ancient machinery repeatedly to get it working, even though his teammate is far more efficient with machinery.
 * In Final Fantasy X-2, the commsphere that Shinra threw into the Farplane Abyss malfunctions and won't connect. Leblanc whacks Shinra's control panel with her fan-weapon and suddenly it connects.
 * Another example in Final Fantasy VIII. Zell does try to fix a machine the traditional way, but eventually gives it a kick out of frustration. The machine works fine afterwards. Zell's example is somewhat of a subversion though, as while it will does fix the machine and open the door to the dungeon, it also forces you to fight a series of tedious and difficult monster battles. While if you go about the slightly more tedious way of acquiring enough points to open the door normally, you can chose whether or not to fight the monsters.
 * In the same game, Selphie shuts off the power to the missile base by slamming a control panel repeatedly. (This was the intended result)
 * In Final Fantasy VII there is a malfunctioning vending machine in the break room of the Shinra building. If you try to hit it, the lady present will stop you. But if you return here during the "Raid on Midgar" event much later in the game, the lady is gone and you can bash the machine for a strength source.
 * In Final Fantasy Fables: Chocobo's Dungeon, the barkeep turns his jukebox on by kicking it, then tells Chocobo that changing audio tracks is done the same way.
 * Shadow the Hedgehog
 * Shadow manages to not only bypass Eggman's security systems, but to bodily enter cyberspace by karate chopping a computer terminal.
 * Charmy also does this later in the game  Interestingly, in both instances, Espio tried to conventionally hack into a database of some sort with little success.
 * Makai Kingdom gives us the Wrench weapon, which can repair vehicles with the Tech Bash skill.
 * In Wild ARMs 2, using Brad's kick ability on a malfunctioning computer terminal in the prison level makes it work again, giving you access to a room with a few bonus stat boosters.
 * In Warhawk (1995 video game), this trope is literally played straight: A few whacks from a wrench will repair vehicles and defenses.
 * Ratchet and Clank
 * In Ratchet and Clank Up Your Arsenal, Big Bad robot Mad Scientist Dr. Nefarious has a habit of having screaming outbursts that make his circuitry overload causing him to freeze in place and broadcast a random soap opera. The problem is easily solved by someone (usually Lawrence) whacking Nefarious in the head (an act that Lawrence calls "the best part of (his) day"), after which Nefarious proceeds as if nothing had happened.
 * Also makes a brief appearance in the first game, when Ratchet repairs a drill by whacking it with a fist.
 * In Rollercoaster Tycoon, mechanics fix broken down shops by kicking them.
 * In Lego Indiana Jones, one of the random animations when using a wrench to fix something is hitting it with the wrench.
 * In The Sims 3 you can "upgrade" appliances by... hitting them with hammers. And let's not forget fixing broken appliances by poking them with a screwdriver. If only...
 * Happens near the end of Metal Slug 3, when the player has to escape from the alien mothership. The formerly kidnapped member pushes some keys on a console/computer and then gives it a kick, and only then the hatch opens to release them.
 * A futuristic stage in Spyro 2: Ripto's Rage/Gateway to Glimmer has a maintenance droid suggest you do just that in order to get various broken-down mechanics working again.


 * You can play Savage: The Battle for Newerth entirely with melee if you want to. It's probably done to keep things simple. Building, repairing structures, mining and claiming spawn flags are all done with melee. The people at newerth.com at some point said they were thinking about adding different animations for the different actions depending on what you're aiming at but they never got around to adding it.
 * In the Super Nintendo beat-em-up game The Peace Keepers, in one level your hero finds that the bad guys have rigged the plane you're on to crash. The only way to prevent it from crashing is to completely destroy all the control consoles so the autopilot kicks in.
 * In the Commodore 64 game Super Pipeline and its sequel, your helpers fix leaky pipes by hitting the pipes with their hammers.
 * In the introductory cutscene for Donkey Kong 64, King K. Rool's shiny new gun is being readied by his idiot mook Kremlings. It starts to power down for no discernable reason, so one of the Kremlings gives it a nice head-butt, which causes it to power back up again.
 * In Zork: The Undiscovered Underground, the player's lantern has been through "several cycles of impact revitalisation", and needs to be given at least one more.
 * The iPhone app Vending Machine Champ.
 * In Space Quest V: The Next Mutation, the SCS Eureka's Chief (and only) Engineer Cliffy (that's "Clifford" to you) fixes things by first actually tightening something, then whacking away at them with a wrench or kicking them. Given that the entire Space Quest verse runs on the Rule of Funny, this makes total sense. (He's actually an incredibly competent engineer, rebuilding a destroyed droid and integrating an incompatible piece of tech into the SCS Eureka without any problem)
 * In the 3D Fallout games, a common jam animation involves the player character whacking the malfunctioning weapon.
 * Portal 2: Wheatley seems to take this method of hacking. For example, he attempts a "manual override" on a "docking gate," which is actually a wall, by slamming Chell's relaxation chamber into it.
 * In Batman: Arkham Asylum, there's a part where Batman needs to use a control panel to turn on a ventilation system. Instead of approaching it and using it manually, he throws a batarang, effectively destroying the panel. The ventilation system turns on as if Batman had used the panel properly.
 * The scene mentioned above from Martian Successor Nadesico also occurs in Super Robot Wars J, only with even MORE Mad Scientists and Gadgeteer Geniuses standing around with no idea on how to deal with the malfunctioning Hyperspace Communicator before Ruri applies some Percussive Maintenance, stunning everyone when it actually WORKS...
 * Mega Man Powered Up: If the protagonist destroys Dr. Wily's combat machine on Normal or Hard, Wily rebuilds it—and make-- it fly - by hitting parts of the cockpit with a hammer several times.
 * In Assassin's Creed: Revelations, Ezio solves a Clock Punk puzzle that has been under water and presumably has some gunk in the gears. It grinds to a halt, and he kicks it to get it moving again.
 * In the reboot of Syndicate, Agent Kilo's DART 6 chip is activated by a Mook punching him, this actually Makes Sense in Context as the opening sequence says it is fueled by adrenaline.
 * In Mass Effect 3 there are a couple of sections where Shepard needs to send one of his squadmates off to hack an important device. If you send James to do it, however, the game makes it clear he's not the techy type by having him kick the thing. Repeatedly.

Visual Novels

 * In Tokimeki Memorial 2 Substories: Leaping School Festival, Homura tries to do this on her malfunctioning TV, first with punches, then with a Dragon Kick. All she gets from this is a completely broken and unusable TV. "Finishing blow!" ("Todome da!") indeed.

Web Animation

 * Active Desktop Recovery flash animation by JohnSu demonstrates how this works.

Web Comics
"Clippy: You don't hit the box or the monitor when your computer malfunctions, do you? Varroa: (innocently whistling) Clippy: Oh dear. You're one of those people."
 * User Friendly has several instances of "percussive maintenance".
 * Referenced in Molten Blade
 * How do you get Dominic Deegan out of a trance? While it didn't work, Dominic's mother's trick was worth a try. The next attempt will probably work better.
 * Percussive Maintenance applied to a baby.
 * Schlock Mercenary has Tagon asking a medical computer whether it couldn't do illegal biomodifications or wouldn't. The computer asked the difference, and Tagon explained that hardware that can't do something gets replaced. Hardware that won't do something gets abused until it will, or until it can't. It then agrees to perform illegal biomodifications.
 * A regular enough practice in Girl Genius. Very few "Sparks" are subtle, especially when they're in a hurry.
 * Rogue in Exterminatus Now knows how to fix his Lightsaber in the field.
 * The Whiteboard: Doc demonstrates the procedure, in this strip.
 * In The Inexplicable Adventures of Bob, Jean's ex-boyfriend Slick can do Fonzie's jukebox trick.
 * The Sergeant from True Magic proves that this works on magical devices just as well as physical ones.
 * Freefall doesn't show this happen, but robots get to say what they think about it.

Web Original

 * In The Dr. Steel Show, Episode 3, Doctor Steel's last resort in silencing a broken videophone is to take a giant sledgehammer to it.
 * In the Gorillaz universe, the mechanic Murdoc hired to work on Plasic Beach insists on repairing the malfunctioning devices with a frying pan. Unlike most examples, he doesn't want to get the things to work in the first place—he's just a lazy guy who's hoping to get more cash out of it, as he eagerly explains in the Plastic Beach adventure game on the official site.
 * From Cracked.com: "I've even seen people who insist that their televisions or vehicles require a special touch that only they know, a touch that usually turns out to be a pretty substantial punch or kick, which I guess makes their superpower physical abuse?"

Western Animation
"Piggy: Kermit, step on it! Kermit: (turning the key) Gee, uh... the motor won't start, Piggy. Piggy: WHAT?! (he keeps turning the key to no avail as the trains get closer) Piggy: (reaches forward and karate chops the hood) HI-YAH! (motor starts) Kermit: Thanks, Piggy. Piggy: You're welcome. Now get us outta here!"
 * In an episode of Family Guy, Peter tried to pull this jukebox at the school. Unfortunately, he hit the glass too hard and broke it, cutting his hand rather badly (though this did have the side effect of everyone thinking he was cool). And Fonzie was shown fixing a old guy's erection this way. Ehh!
 * The Simpsons—Same thing happened to Homer Simpson.
 * Futurama
 * Subversion: the TV signal goes out because of interference from Bender. Fry hits the TV just as Bender leaves the room, and does Fonz's thumbs-up "Hey!" when the signal returns.
 * Played for laughs in Bender's Game where the Hal Institute for Criminally Insane Robots uses hammer therapy on its patients.
 * In the episode "Bender Should Not be Allowed on TV" a Antonio Calculon Junior breaks down. Someone comes by and hits him on the head a couple of times. it didn't work.
 * The Fonz himself is featured in The Fonz and the Happy Days Gang, employing his trademarked fix in order to, among other things, repair a time-traveling flying saucer, vehicle of choice of the gang in the cartoon. In several chapters the Percussive Maintenance (usually in the form of a finger snap) is even seen stopping and reversing inertial momentum (!).
 * Daria does this with Trent's van, "The Tank". After it makes a certain, strange noise, there's a ten count, followed by a punch to the dashboard, and suddenly everything's right as rain.
 * Muppet Babies: The kids are in an old roofless police car on railroad tracks with two trains coming.

"Kairo: With my radio, sometimes this makes it work."
 * In Peanuts, Lucy used this method to "fix" an invisible Charlie Brown, saying that it's the same principle that fixes the picture on a television.
 * Averted on Beavis and Butthead when the title duo try to get their TV working again with numerous kicks. Pieces fly off, but that's all that happens. Due in part to a citywide power outage they don't notice.
 * In The Penguins of Madagascar, Skipper tries to smack a malfunctioning flashlight. It works... for all of about three seconds, and then fizzles out again.
 * In an episode of Pucca Abyo try to do this with a kick, searching to repair a problem with the time clock of the Master Soo's temple,, but he couldn't repair the problem. Their two attempts caused . Then, the Master Soo came and with a punch he can solve the problem with the clock... or well,.
 * In Turtles Forever, Donatello initially ridicules his interdimensional counterpart when he tries to apply this philosophy to their transdimensional portal stick. Guess what Donny eventually has to do to eventually save their shells.
 * An episode of The Fairly OddParents parodies the concept... by jamming an axe into the TV. And it works. Twice.
 * In The Ultimate Silly Song Countdown, the machine used to tally the votes occasionally breaks down, and Pa Grape uses a wooden mallet to fix it. At one point, he has to hammer it so much that Mr. Lunt and Larry have to improvise a song in the meantime, and they use his "percussion" (and a Chinese takeout menu) as inspiration.
 * The Transformers, episode "Cosmic Rust". After trying to get the matter duplicator to work to replicate more Corrorstop to cure the Autobots of said disease, it's Perceptor who resorts to this.
 * On Jimmy Two Shoes, this is how Heloise fixes her Brainiac Booster.
 * The Flintstones: Fred Flintstone is a master TV repair man, providing he has his club.
 * Filmation's 1960's Green Lantern cartoon. In the episode "Evil Is As Evil Does", the title character's power battery has stopped working.

"Dr. Doof: Oh hey, random pounding works."
 * Lampshaded in the Phineas and Ferb episode, "Hide and Seek" when Dr. Doof tries gets his Incredibly Obvious Bug working by after repeatedly hitting his monitor.


 * During an episode of King of the Hill, the horn on Hank's truck is stuck blaring, thanks to Bobby knocking it out of park and into the garage door. After a few moments, an annoyed Dale walks outside, delivers a kick to the trucks side, and the horn stops. Though Hank tells him to "Not even try and take credit for it."
 * Johnny Test. With earth under alien invasion, and the twins stuck trying to get the earth's defense grid going, Susan can't figure it out, so Mary gets it going with good swift kick.
 * In Wacky Races the Slag brothers often does this to their stone age car. Once though, the car hit back. The other racers also does this from time to time; Peter Perfect once fixes his car that had completely fallen apart with one kick.

Real Life
"Customer: My system won't boot. Support: < > OK, take the hard drive out, hold it, and slam it against the desk. No, harder. No, harder. No, harder. OK, put it back in. < > Yeah, we got a run of bad hard drives that stick, and slamming them on the desk like that will temporarily unstick them. I'm sending you a replacement unit."
 * During the Apollo 16 mission, an alarm light kept malfunctioning until commander John Young tried kicking it. When he reported success, the response from Earth was "It's an old American custom: kick it if it doesn't work."
 * Apollo 12: Alan Bean was instructed to try and fix the camera by tapping it with his hammer. He radioed, "I hit it on the top with my hammer. I figured we didn't have a thing to lose. I just pounded it on the top with this hammer that I've got." The capsule communicator in Houston joked, "Skillful fix, Al." Bean agreed, "Yes, that's skilled craftsmanship."
 * Alan Bean had the job of removing the plutonium source from the cask and inserting it into the generator but after he pulled it partway out, it stuck and refused to budge any farther. After a few minutes of fiddling with the long-handled removal tool, Bean got frustrated and suggested that they give the cask a couple of good whacks with the hammer. Conrad wasn't quite ready to be so unsubtle and wanted to try using the hammer as a prying tool. But, when that didn't work either, he, too, gave in to the inevitable and gave the cask a good, sharp rap. The fuel element slid out a fraction of an inch. He hit it again and harder. And again. And that did it.
 * Alan Bean still has that hammer to this day, and uses it to add textures to his paintings.
 * Apollo 14: While running through the pre-PDI checklist, Al Shepard and Ed Mitchell noticed that the abort light had come on, indicating that the computer had gone straight into abort mode. If this happened during the actual burn the computer would abort the descent and that would be mission over as there'd no longer be enough fuel for another attempt at landing. They got the light to go out by tapping on the console with a pen. Of course this was only a temporary fix, and a more elegant solution requires some in-flight reprogramming of the guidance computer (by tricking it into thinking it was already in abort mode it would not monitor the status of the abort button). The moment is recreated in the Apollo 14 episode of From the Earth To The Moon.
 * The first Skylab mission (the one that had to fix all the major malfunctions that were mostly the result of one solar wing trying to deploy during the damn launch) had a problem with the small solar array hardware having accumulated static. The fixed it by thumping it during a spacewalk. (This works on certain classes of electronics prone to malfunction due to static electricity build up. A suitable thump will help disperse it.)
 * World War I fighter pilots often kept a small hammer in their cockpits in the event that their machine guns jammed.
 * 999 had a real life story where a couple were trapped in a car with its engine on fire and but found the electric locks wouldn't open. The husband in desperation started belting the steering column with his hands multiple times, until the locks suddenly opened on their own.
 * Familiar enough among musicians to become a joke. "Percussive Maintenance: Having to hit something with a hammer a few times to get it to work properly."
 * If you call up the Nintendo Tech Support line with a Wii Mote problem, and they diagnose it as a stuck accelerometer, the fix they give over the phone is to, quote, "Hold the Wii remote buttons-side down, and whack it into your palm loud enough so I can hear it over the phone." It works.
 * A 1980s guide to console gaming:
 * Step 1: Insert cartridge.
 * Step 2: Turn on console.
 * Step 3: Turn off console.
 * Step 4: Remove cartridge.
 * Step 5: Blow on cartridge.
 * Step 6: Blow in console slot.
 * Step 7: ????
 * Step 8: Profit!
 * Don't forget "jiggle cartridge in slot" and "cram folded pieces of paper of varying thicknesses in between the cartridge and the walls of the slot".
 * Also, only the console's owner can do this. Anyone else attempting to blow in the cartridge and/or console slot will invariably fail to correct the problem.
 * It should be noted that Step 7 isn't just applied here as a Memetic Mutation. If you get to this point and it doesn't work, keep doing random things to the cartridge and\or system until it works, because it will.
 * Step 8, however, is.
 * Best way to deal with step 7 is: "START WORKING YOU PIECE OF MOTHERFUCKING SHIT OR I SHOVE AN AXE INTO YOU AND BURN YOU ON A CROSS!!!!" Usually works. At least when you stand up to pick the said axe.
 * Q-tips and rubbing alcohol are cheaper. Also, they keep the system/cartridge cleaner for longer, while blowing into a cartridge can actually corrode the metal contacts over time from the moisture in your breath.
 * This is, believe it or not, one of the many ways to (temporarily) cure the Red Rings of Death on Xbox 360s. (Another one is baking, mentioned later on this page for GP Us - because the fault *is* in fact an unsoldered GPU.)
 * Back when Apple was not only called Apple Computer but they made computers besides Macintoshes, their big, expensive (and most importantly, fanless and made of solid aluminum) Apple III models had an issue where the computer would run so hot, its chips would unsolder themselves. The official tech support solution was "raise the CPU three to four inches off the desk and release it," which usually re-seated the components.
 * Cards/components in early Macintoshes of all types would creep out of their sockets from thermal expansion/contraction cycles due to high operating temperature. Mostly affected units turned off/on daily. The solution was to pick up the case and drop it. Sometimes just carrying the unit would reseat the cards. Tech support's solution? "Just bring it in." They'd let it sit untouched for a day, then have the user come pick it up. The joggling from the transport fixed the problem. Easier than explaining.
 * Not only early Macintoshes. Early PCs as well. And even modern day PCs with cases manufactured under questionable quality control will have this problem. The author of "Building and Maintaining Your PC" called this issue "card creep", although his advice was a more sensible albeit time consuming "open the PC up and push every single card and RAM bar down". Yeah, a applying percussive force from the top fixes things too in many cases.
 * When Commodore was producing Amiga 500's in its West Chester, PA facility, the engineers and other employees became fond of drag racing on the parking lot. Subtler means having failed to dissuade this practise the company had speed bumps of ever-increasing size installed. The bumps got to the point of shaking the shipping trucks so much that the socketed main chips would loosen in the motherboards, causing sporadic failure. It got to the point where dealers were instructed to take their freshly delivered machines and drop them several feet to reseat the chips.
 * Atari ST enthusiasts are familiar with something similar, called the Universal 4 Inch Drop. And for pretty much the same reason as the above Apple IIIs.
 * The unofficial solution for problems with some iPods with sticky hard drives is to whack it against a table.
 * This is one of the reasons why PCI-E slots (commonly used for Graphics Cards) are often outfitted with a plastic hook which will click into a small slit (or 'key') in the card. The card cannot be moved in the slot unless the hook is pulled back first.
 * Sun Microsystems had a period of time where a lot of tech support calls went like this:

"A novice was trying to fix a broken Lisp machine by turning the power off and on. [Tom] Knight, seeing what the student was doing, spoke sternly: "You cannot fix a machine by just power-cycling it with no understanding of what is going wrong." Knight turned the machine off and on. The machine worked."
 * Banging the top with a closed fist sometimes does wonders with old CRT screens that have a recurring "picture suddenly compresses into a single horizontal line" issue. This is also the officially recommended way of dealing with aperture grille displays when their thin vertical wires stick together.
 * In the Church of the SubGenius, the laying of hands on malfunctioning equipment, done swiftly and sharply, is called "Appliance Healing".
 * Any British geek of late 70s/early 80s vintage worth his or her salt can tell you what a balky piece of equipment the typical Sinclair computer was. The fact that the most common storage device was a common or garden domestic tape recorder didn't help matters in the least. The tinkering that ZX-80/ZX-81/Spectrum owners would engage in with azimuth adjustment screws, volume and tone knobs, cabling position, tape recorder position, computer position and a dozen other things became almost ritualistic. But when all that failed, just whacking the tape recorder, or the computer, or the power supply brick would actually work on a disturbingly regular basis. Some still remember having to keep their feet on the power brick otherwise the dreaded R: Tape Loading Error message would pop up.
 * A good thump can cause loose wires to reconnect; the electricity flowing through them will hold them in place.
 * Carowinds, a theme park on the North Carolina/South Carolina border, has a roller coaster called the Carolina Cyclone with a few restraint bars that have a habit of getting stuck. The correct method of unsticking them, as ride attendants are instructed during training, is to kick them.
 * One of the first things to try when clearing a weapon jam is to simply smack the magazine, which it is also recommended you do before loading the magazine in the first place. A few good mag taps on a rock before loading will do wonders for a weapon.
 * Or on your helmet.
 * This is more part of a general "weapon does not fire" drill. You don't "smack" the magazine—rather, you check to make sure it is properly engaged. Then you check the breach for an obstructing round. And if any of my instructors saw you tap your magazine on anything other than your palm prior to loading, you'd be subjected to a lecture, and then probably a quick jog... just to make it sink in.
 * Apart from CPR, another technique used in emergency medicine is the precordial thump, which involves laying a carefully aimed blow to the chest at just the right time to convert a witnessed cardiac arrest. (Contraindications include "Presence of a pulse.")
 * CPR is another example, effectively meaning "compress heart repeatedly (with good rhythm) and forcefully (it frequently breaks ribs) to make it go". Similarly if someone is choking the procedure is "encourage to cough" > bash them in the back (back-slaps) > bash them in the front (chest-thrust, a.k.a. the Heimlich manoeuvre), which can also do some damage, but better than suffocating.
 * Similarly you can help reduce bleeding by applying pressure to the wound. First Aid: Curing violence with more clever violence!
 * Engineer's Creed: "If it moves, and it shouldn't move, use duct tape. If it doesn't move, and it should move, use a hammer."
 * Add a can of WD-40, a pocket-knife, and a six-pack, and you have the Redneck Tool Kit.
 * This is an actual maintenance procedure in U.S. Navy engineering manuals, under the name, "Mechanical agitation".
 * Every troper should know that this is the best solution when a machine does not register the quarter you just put in or does not deliver the promised change.
 * Or when it hogs your chips. There's even an iPhone app for it.
 * The Technical Manuals for old military analog man-portable radios (such as the PRC-25/PRC-77) suggest a drop of one to three feet onto a solid surface as part of operator-level maintenance.
 * Slot machines typically have several different doors leading to various parts of their innards. Sensors are connected to the doors, and generate a tilt whenever they register as being open. Unfortunately, sometimes the machine will be manhandled to the point where closed doors will still show to the machine as being open. An experienced slot attendant often knows how to diagnose which door is the problem and clear the error with one well-placed smack, without going through the trouble of actually opening the door and adjusting the sensor (which often involves filling out logs and other red tape).
 * Recorded Books Incorporated used to put on their cassette tapes that if you ever ran into any problems with tape, you should "place it in the palm of your hand and slap it smartly against a hard, flat surface." If that didn't work, and you could not "otherwise free the reels," then you could send it in for a free replacement.
 * Modern vending machines all have messages warning you against tipping the machine or reaching up into it in order to free the things that are stuck there. (That doesn't stop people from trying, and getting hurt in the process.)
 * You don't have to tip the vending machine to get something dangling. A good few hits with one's shoulder is usually sufficient to dislodge something. The downside is that ramming one's shoulder into a piece of hard plastic can be quite painful.
 * London, Brighton and South Coast Railway locomotives had a special hammer for this purpose as part of their standard toolkit. The business end was made of lead, to reduce the risk that it would damage the paintwork.
 * Renowned Soviet T-34 tank had a very poor transmission/steering design, unfaithfully copying an American project of the late 1930s which hadn't get put into production exactly because it didn't work. The massive iron levers which actuated the steering and gearshift would often get stuck, even worse in freezing temperaturs which are typical to Russia, and they had to be moved with a hammer. There were hammers issued to tank drivers just for this purpose.
 * The key-insert for some older models of Saturn gets stuck, usually due to temperature change making the bits inside swell/shrink/shift. The best (only?) solution: smack it hard and firm a couple of times. Inspires great confidence in new passengers.
 * Apparently, there is/was a car used by the US Army that was fixed like this. This particular make and model would always break down in the exact same way and could always be fixed with the same method: kicking in just the right spot under the dash. There was actually a "painting duty" the soldiers had every so often where they would paint/repaint a red circle over the spot so the driver knew where to aim his foot without having to look/think too hard about it.
 * Subverted with fatal consequences for Jasper "Jack" Daniel (founder of Jack Daniel's distillery), who broke his toe kicking a safe he couldn't open. The break became infected and Daniel died of sepsis.
 * Also, it didn't open the safe.
 * Spanking
 * This is often the only way to fix a hard drive with a hard crash, or "Tick of Death".
 * Freezing the hard drive also frequently works well, but in both cases don't rely on the drive lasting longer than a few minutes
 * Works quite well if something like a remote control or calculator has a loose battery.
 * This guy used this technique successfully on a plasma TV. With a baseball bat.
 * The Hayabusa mission was supposed to return a capsule with samples of an asteroid. Due to some technical problem, it returned with only very small particles of dust, which had to be carefully extracted to be examined. In the end, the procedure they used was: [[https://earthandsolarsystem.wordpress.com/2011/03/11/blogging-from-lpsc-
 * This is also known to many people as an "RCA Kick" - as in, give that TV an RCA kick to get the v-hold back in line.
 * Related to destructive repair techniques is "Baking" a delicate and highly technical process of getting a video card with screen artifacting to work again by literally baking it in a 380F oven for 8–10 minutes. particular interest to Nvidia 8800 and 9800 owners
 * Which works because official way of mounting a BGA chip on a board is baking it in a special oven. Re-baking in a home oven restores any disconnected solder joints the chips may have.
 * At least supposedly, some phone techs will ask users to tap their computer on the back side of the case. This is actually a subversion - the point is that in doing so, they'll look at the back and notice if a cord is unplugged, while if you ask them whether the network/power/etc is plugged in they'll get defensive.
 * One of the so-called "AI Koans" told at MIT has this as a variation:


 * (The moral being that knowing what was wrong was enough to fix it, apparently.) This was supposedly based on an actual incident; some variations of the story involve hitting the machine instead of power-cycling it.
 * This is a common quick fix for automotive starters. Most of the time the starter doesn't work because the throw-out bearing is bad. Hitting it with a hammer is often enough to get it to let the starter gear to engage the flywheel and turn the engine over.
 * Carburetors are preferred over electronic fuel injection precisely because they can be fixed with Percussive Maintenance when stuck.