In InuYasha, the title character accidentally damages the handlebar to Kagome's new bicycle. While she goes to school, he volunteers to fix it. Given his lack of knowledge on bicycles - or anything else from the modern era for that matter - things quickly get out of hand, and by the time Kagome gets home, the bike is in even worse shape.
Roger makes a habit of this in FoxTrot. In his best effort, he manages to burn his silhouette onto the wall while trying to light the furnace.
In his defense it was because of a weirdly worded safety feature. He thought he turned off the gas when he actually just turned it on full blast. The settings were "Auto" And "Off". Off means that you turn off the regulator on it.
Calvin occasionally tries to fix things around the house (including more than one ill-fated plumbing incident), and usually ends up causing more destruction than when he tries to destroy things.
MTM: And yet, this isn't half as dangerous as the time your Dad tried to fix the toaster.
The basic plot of the Buster Keaton film, One Week. The newlyweds try to build a house with a full kit, but a rival sabotages the parts numbering. Obviously, professional house builders could have spotted the problem long before the couple does.
The Three Stooges are pretty much the kings of this trope. One short has them building a dream house for their wives, which ends up being something out of a Picasso painting with a set to stairs leading to nowhere and a door on its side.
Jack Prelutsky takes this to comically exaggerated heights in his poem "I Wish My Father Wouldn't Fix Things Anymore." (note: PDF link) Everything the father in question fixes works after a fashion, but not in quite the intended way—for instance, a toaster that previously didn't pop now pops even when disconnected.
In Diane Duane's A Wizard Alone, Senior wizard Carl provides an instance of this when Kit stops by and finds him trying to rewire the lights in the kitchen, despite his housemate's repeated suggestion that he call an electrician:
"We're expert enough to change the laws of physics temporarily," Carl muttered. "How hard can wiring be?"
Bree Pym decides to repaint her bedroom early in Aunt Dimity and the Lost Prince. Unfortunately, she does so during a February cold snap and cannot open the windows for ventilation without risking freezing and/or bursting the plumbing pipes. This brings her to Lori's doorstep in hopes of a place to stay for a few days.
Live Action TV
Practically the whole shtick of Home Improvement's Tim Taylor, who would (of course) apply Tim Taylor Technology. (Except of course when it did work. This usually occurred when he stopped assuming he was doing it right and did things like double-check measurements and read the manual.)
Then again, this mostly happened on his Show Within a Show "Tool Time," which was basically stated to play up accidents and foolery for fun and ratings' sake (right before the blow up the set on purpose) - when he fixes things at home he tends to be infinitely more meticulous and effective.
The Red Green Show got a lot of mileage out of this trope. "If it ain't broke...you're not tryin'."
In one episode he claimed he was inspired by his grandfather (who apparently had the nickname "Grandpa Hook" because of this).
Its All Relative did this in one of its few episodes: the son-in-law to be breaks his fiancée's gay dads' fancy cappuccino machine, and his father tries (and fails) to fix it.
In the Fawlty Towers episode 'Gourmet Night' Basil insists on fixing the car himself despite Sybill's ordes, resulting (of course) in the car being unfit for use when he most needs it.
Endlessly on Top Gear — the presenters have tried to build their own electric car, space shuttlenote fortunately for The BBC's public liability insurance premiums, the rocket stages accompanying the space shuttle were outsourced to people who actually knew what they were doing, and "Mitsubishi Evo" (nee Renault Avantime), generally for less than the cost of the real thing. Leads to a Crowning Moment of Funny if the thing fails or a Crowning Moment Of Awesome if it succeeds, so it's great entertainment either way.
The Ground Force crossover for Sports Relief involved applying this trope to somebody else's property. The only part that wasn't Played for Laughs was the reaction shot from the guy who owned the place, who was not pleased.
And inverted on fellow DIY show Disaster House. The point of that show is to take a house already scheduled for demolition and intentionally inflict all manner of calamities upon it until such time as they do something so bad to the house that the insurance company calls the whole building a write-off, at which point they tear it down as originally planned and start again with another house. After the anvil has been rolled down the staircase, the car has been driven through the garage at speed, the herd of sheep has finished their pooping session, the elephant has finished clogging the toilet, the indoor lucha libre match or roller derby has concluded, the sand castle has been blown apart with C4, or the piano has been dropped through the roof, then and only then do they get around to undoing what their chaos has wrought. Discussions of what insurance will cover and pleas to leave things to the professionals due to the sheer scale of the disaster in question are common. (The thing that finally did in the first house, by the way: simulating ice and snow buildup with a garbage truck. Placed on the roof.)
Carl on Family Matters was infamous for being absolutely terrible with housework, yet determined to be a man and fix it himself to save a few bucks. A Noodle Incident involving a spice rack ended up with the family staying in a hotel for a week while professionals fixed the mess, just to give you an idea. He tried to install a shower for his mother and somehow ended up crossing the pipes so turning on the sink turned the shower on. That's how bad he is. He also almost burned the house down trying to fix a toaster, and his birdhouse was condemned by the Audubon Society. Perhaps more poignantly, he also electrocuted himself trying to fix a lamp and would have died if Steve Urkel hadn't performed CPR to save his life.
The entire point behind Canada's Worst Handyman, a Spin-Off of a similar series for driving. Five handymen are taken to a building in need of renovation with the person that nominated them. They are given a series of challenges, ranging from making a worktable to installing a ceiling fan to installing disco balls. The show also includes several challenges where all five handymen are brought together to do a larger project. The end of each episode includes ‘Most Improved’ who leads the next group challenge and ‘The Worst’ who is given ‘homework’ to do with the host. At the end of a season, the host and two experts decide that season’s worst.
The guys on Pawn Stars are frequently offered classic cars, which can sell for huge prices. Unfortunately, some of these cars' owners did their own mechanical work, and it turns out they were so incompetent that they actually weakened their cars' performances and resale values. As a result, Rick Harrison and his crew frequently have to turn the car owners down, because it'll cost more to get the cars working properly than they'll be able to sell them for.
Also common with antique metal objects, especially guns. People find them and decide to clean them up with steel wool, destroying all value from the object.
Emergency! has an episode where the paramedic truck breaks down and the Paramedics decide to fix it themselves, much to the annoyance of the regular mechanic who doesn't appreciate them doing his job. Sure enough, the truck keeps breaking down which forces them to abort dispatches. The mechanic eventually solves the problem and the Station Captain bluntly tells the paramedics to leave future mechanical problems to him.
Hannah Montana: When Jackson learned how much plumbers usually charge for their work, he convinced his Dad to hire him for a smaller (but still big enough to convince Jackson) amount. Jackson's Dad was furious at the results and called a professional plumber. Surprisingly, the plumber concluded Jackson actually prevented something worse from happening and said Jackson could be a professional plumber.
The cast of MythBusters often does this on purpose, disabling safety features on the items they test in order to see how catastrophically they can fail. For example, in several myths involving water heaters, Adam and Jamie blocked off the safety valve so that the heater would explode once enough pressure built up.
Judge Philip Banks was a highly respected attorney, and becoming a judge only improved his reputation. Unfortunately, he crossed into full Bumbling Dad mode whenever he tried to fix something around the house. His attempt at fixing the stove burned off his butler Geoffrey's eyebrows, his attempt at fixing the toaster caused Geoffrey to get hit in the eye with a piece of toast, his attempt at fixing the phone killed the line, and his attempt at fixing the sink caused a major leak.
Parodied in "Power Tools" by Ray Stevens. The narrator finds himself wanting to fix things up, but Hilarity Ensues. When he ends up in the hospital, he ends up obsessing over his power bed... and then getting stuck in it.
"When Father Papered the Parlour", which debuted in 1910, begins in the approved manner with Father announcing that it would be wasteful to pay professionals when he can do the job himself, and continues on with several verses' worth of disaster, including the misterious disappearance of the piano, and a glue catastrophe that results in one of the daughters having to be hurriedly married off to her boyfriend because they've become literally inseperable.
Many episodes of The Phil Harris Alice Faye Show use this trope, from coloring Julius' hair with fabric dye, fixing the dishwasher with disastrous results, to buying a live steer to save money on steak (which it doesn't).
Code Lyoko: Sissi's Bumbling Dad Jean-Pierre Delmas boasts to be skilled with small electronic devices... but when he tries repairing his daughter's cellphone, he ends up stabbing it with a screwdriver. (It did spare Sissi from being controlled by XANA's next attack through cell phones though.)
One episode of Sitting Ducks had the main duck try to install a satelite TV dish by himself. Not only does Hilarity Ensue, but his antics make the news, where the anchorman (Er, duck) refers to him as a 'hapless do-it-yourselfer'.
Charlie Bear, from a segment of The Woody Woodpecker Show, would always try (and fail) to do things by himself to save money. Of course, that includes things his wife would rather call a plumber.
Andy Panda's father tried to tar his roof to save the money he'd have to spend if he hired a professional. Seeing the results would make Mrs. Bear glad she's not Mrs. Panda.
Hanna-Barbera character Wally Gator also fell victim of this trope. Long story short: by the time he started believing a plumber would be needed, the zookeeper told him to call the coast guard instead.
The Looney Tunes Show: "The Shelf" begins with Bugs Bunny refusing to pay the hardware store $20 to install a shelf, insisting he can do it himself. By the end of the episode, he has demolished his house.
Batman: The Brave and the Bold: The 'Mazing Man story in "Four Star Spectacular!" revolves around 'Mazing Man repeatedly demolishing and rebuilding a fireplace in an attempt to rescue a cat, with predictable results.
Dogstar: In "The Quick and the Dog", Zeke attempts to fix the food synthesizer. It results in him and Alice being drenched in dog food.
It's not just dads who fall victim to this trope. Virtually everyone having to 'make do' with a damaged implement in an emergency (or from lack of funds) can coax it to work with a little jury-rigging or Percussive Maintenance, which makes the user think the problem is really fixed and continue using it without a proper repair. The latter is often what really destroys the implement in the end by aggravating the initial defect.
A Dave Barry column deals with the columnist's attempts to do this with his plumbing system. Highlights include "a spider the size of Mike Tyson" and Barry's assertion that the Roman Empire collapsed when they tried to install plumbing in it.note Romans got lead poisoning from plenty of sources, but lead pipes were not a major contributor — the lead in the pipes was quickly coated with a plaque made from minerals in the water. Using Lead(II) acetate as a sugar substitute, on the other hand... Dave Barry also has a Doom It Yourselfbook called The Taming of the Screw.
If the dad in question is one of those "doesn't read the manual" types, this can very well turn into Truth in Television. Even if he gets it right, it almost always takes such an unexpected amount of time and money that it'd be easier to just hire a pro in the first place.
College kids in dorm rooms also fall victim to this trope, especially when it's something the school's maintenance team doesn't repair. A little bit of duct-tape, some creative thinking, and....voila! Instantly fixed. Also an instant fire-hazard, but the joy of triumph overshadows anything else. At least for the next three days, until it breaks... again. And catches fire this time.
In an IRL example, there's a common misconception that the notorious Red and Yellow Lights Of Death (or "RROD" and "YLOD") on the Xbox 360 and PS3 (respectively) can be fixed by blasting the graphics chips on the systems with hot air from a heat gun, and many tutorials exist on Youtube demonstrating how to "repair" your game console in this manner. The fact of the matter is that this is at best only a temporary fix, and in most instances it actually causes irreparable damage to the GPU's heat sensors and the system motherboard, to the point where even a professional may be unable to repair the system. Long story short: unless you know how to operate a machine that looks like this◊, you should not be trying to repair a fried game console.
With the release of Xbox One, a number of gullible users fell for an Internet hoax that gave a list of easy-to-follow instructions on how to make the console backwards compatible with Xbox 360. If you followed the instructions, you ended up putting the console into an infinite reboot loop that made it unusable.
Upgrading a PC is usually simple enough to avert this trope, at least on the hardware side of things, but British gaming magazine PC Format once received the following letter (paraphrased from memory):
Dear PC Format,
I was in the middle of installing some more RAM when my flatmate walked up behind me and touched me on the shoulder. Suddenly the screen went blank and my PC has refused to boot up since. He'd been walking barefoot on the nylon carpet and might have picked up a static charge. Does he owe me for a new motherboard?
The correspondent received very little sympathy from the editors. In short, he was trying to install RAM while the system was still turned on.