Ask HN: How do I learn practical electronic repair?
104 comments
·May 31, 2025atonse
Louis Rossmann’s electronics guide was the first time these concepts truly clicked for me: https://youtube.com/playlist?list=PLkVbIsAWN2ltOWmriIdOc5Cti...
Apart from that, just fix broken stuff. Practice like any other skill, like others have said.
Like decide what skills to learn based on what’s broken.
Need to solder something together? Buy the soldering iron. Need to figure out which capacitor you need to replace with? Learn how to identify capacitors and navigate digikey.com
hyperman1
I'd add: Learn to recognize dangers first. From the top of my head:
* big caps that can contain high voltages even when a device is powered off, in TVs or microwaves.
* Know where a fire extinguisher etc is, keep them near the workbench.
* Keep the workbench clean, tidy and well-vented.
* Don't panic when mistakes are made. Slow down instead of doing a quick-fix.
* I like a big red button to power down everything instantly. Can be just a switch on a plug box.
Nextgrid
If you're often working with mains-voltage things, you can use:
* an isolation transformer - meaning you must now touch both conductors to get shocked instead of just the live one
* a foot switch to control the power supply - serves as a "dead man's switch" to cut power in case of an accident
(these are not mutually-exclusive, you can combine them)
ajb
Definitely
Risks to consider in general are (also of the top of my head don't take as exhaustive):
* Electrocution
* Burning yourself
* Setting stuff on fire
* Fumes, both from soldering and overheating/burning plastic
There's a kind of balance between habits and awareness. Rely too much on awareness and you will miss some safety issue during a complicated repair. You need good habits, but rely too much on them and you won't notice when you finally make a mistake.
Those apply during repair processes. It's also possible to render a device unsafe to use, for example by damaging a li-ion battery or by a 'bodge' repair that circumvents a safety feature.
snackbroken
A tip on how to reinforce good safety habits taught to me by my shop class teacher is to refer to any dangerous tool you are using by the kind of injury it is likely to inflict. The lathe is the deglover, the angle grinder is the eye splinter injector, the welder is the retina tanning machine, the soldering station is the IQ diminisher, etc. This helps to put you in the mind of "I need the eye splinter injector for this task, how shall I go about avoiding getting splinters injected into my eyeballs?" instead of getting complacent.
gregoriol
Also let someone know where you are and by what time you plan to have completed the job, could save your life
sriram_malhar
I loved Rossman's explanation of the transistor. Transistor is just a controllable resistor. So simple. No one told me this. I could have saved years!
lsharkey602
I'll just say, "thank you".
globalnode
that playlist actually looks promising, will have a look later.
BigCatStuff
I believe Youtube videos are a great resource for learning this! I picked up electronics and computer/gpu repair as a hobby over the pandemic lockdowns.
A cheap multimeter and a cheap soldering iron/hot air station combo will get you very far in the hobby. I enjoy these channels:
MyMateVince (a guy who fixes many useful household items): https://www.youtube.com/user/mymatevince
StezStixFix: https://www.youtube.com/@StezStixFix
Electronics Repair School (more advanced, he fixes laptops, tvs, and sometimes gpus): https://www.youtube.com/@electronicsrepairschool
ryandrake
YouTube videos are great -if- the problem you're having is exactly the same as the problem the YouTuber is solving. For example, I was able to replace the HDMI capacitors on my A/V receiver because I lucked upon a YT video where the problem I was having was identical to the problem the YouTuber was solving. So it was basically, buy these capacitors, replace them, and off you go. Repair usually just requires basic soldering skills and the ability to put things back together you took apart.
When the problem is not exactly the same, I'm just lost. There is not a lot of diagnosis videos on YouTube. All the videos are: "1. I observed this problem. 2. [???] 3. I'll walk you through soldering on the new components." skipping the most important step 2.
Same for car repair videos: "I see Problem X happening. Problem X usually means component Y has failed. Here's how to replace component Y. The end." If that doesn't work, you wasted money on the part and your time ripping apart your car and putting it back together.
BigCatStuff
I agree that the diagnosis and visual inspection is the most important skill in fixing random items.
In the channels that I suggested, all of them go into the repair not knowing what the fault actually is. They take the viewer through the whole diagnosis, and they (with the exception of Electronics Repair School) are not electronics technicians.
Once a person has seen enough different ways of diagnosing items (by watching videos or hands on trying), then faults in other items become easier to find.
moepstar
What _i'm_ missing from those videos is - while they do go through the steps finding the fault - usually don't really explain their reasoning why they suspect component a, b, c to be faulty and how exactly a good (or bad) component would behave...
Might not be the case for all the vids of course, but for those i watched i never had that "ah, that's how it works" gotcha moment...
sowbug
Big Clive, too. https://youtube.com/@bigclivedotcom
He buys cheap crap, takes it apart, and usually infers a schematic. He also admires or critiques the designs. After a while you'll notice patterns.
analog31
I repair practically anything that breaks in my house -- except heavy work on the car, or the roof. A few things, from me as a kid:
1. Take things apart, and try to figure out how they work. Don't worry too much about getting them back together. But then, trying to reassemble it is good practice too. There's plenty of old electronic junk that you can explore before throwing it away. Build a mental catalog of how things work and are assembled. Among other things, this will help you when you need to come up with a strategy for getting some particular gadget open -- often 9/10 of the problem.
2. Like others have said, YouTube is great. People will make a video of a repair, or even just getting something open, for a few "likes." Also, most of them are just normal genuine people who aren't trying to be influencers, so it's kind of culturally refreshing. Many of my successful repairs started with YouTube, such as my clothes washer and dryer, refrigerator, lawn mower.
3. Many of my most cherished tools are what I call for "demolition," not electronics specific, like picks, pry bars, a slim knife that can get between things, stuff like that. Another set of cherished tools are my magnifying visor, small magnifying glass, bright flashlight, and a stereo inspection microscope that I got second-hand.
4. A lot of "electronic" failures are actually mechanical in nature, and you can just use your general troubleshooting rundown to figure them out. Switches, connectors, cables, etc.
5. Begin to get the hang of identifying parts, and how part numbering schemes work. It will help you in your search for spares.
6. These days I often ask my spouse for a opinion. She's a laboratory scientist, quite sharp and skeptical. I'll have a hypothesis, and she asks the one question that blows it out of the water.
Good luck! Don't get electrocuted or burn your house down.
exe34
> Take things apart, and try to figure out how they work. Don't worry too much about getting them back together. But then, trying to reassemble it is good practice too.
For some reason I got my hands on a lot of old clocks as a child, and after getting the springs out, I never could get them back in. Turns out there's a special lathe you need to use to coil them up tightly enough. Only learnt that when I was about 20.
mikewarot
I've got a friend who has been at this since learning in TV repair shops in the 1950s. His emphasis is always on fast turn-around. He doesn't believe in slowly turning on things with old electrolytic capacitors, for example. I've learned quite a bit from him.
I've learned not to fear B+, but to give very healthy respect to anything more than 500 volts. (Only use 1 hand, keep the other behind you, always have a safety partner, etc)
I've learned to hate Silver Mica capacitors. I've learned how to track down the bad ones that cause the "crashing" sound in old radios.
I've learned that in very old electronics, you can let smoke out, and things will still work. I've gotten good at seeing where the smoke comes from.
You'll definitely need to learn to solder. I'd suggest starting with something like an Arduino starter kit to get a sense of how components actually interact.
But remember, if something is dead, you can't really make it worse. (Just be careful not to make yourself worse along the way)
vel0city
> give very healthy respect to anything more than 500 volts
Man, I'd say be very respectful to anything that might be running 120-240V, and be very sure about anything higher than that. Anything <50V can often just be fun tinker whatever assuming you're ok with breaking whatever you're playing with, up to a certain max amperage of your power source. High amperage but low voltage can still cause some serious messups if you don't have the right fuses in place. But I get other voltages are common in Europe.
prpl
i’ve been hit by 350V trying to bias a tube amp but it was low current (B+). Woke me up
cowboylowrez
yeah I just treat any higher voltage like I would a snake, I stay away haha.
tuatoru
DC, definitely. Above 60V is dangerous.
AC, 120V will 'bite', 240V will make you shaky (remembers id10t maneuver yesterday, first in a decade). And burn you. In damp environments or with corrosion around, much worse things can happen.
moron4hire
Nah, 120v ain't so bad. Hurts less than hitting your finger with a hammer.
vel0city
I'm not necessarily talking about getting shocked (which can still end up being bad), I'm also referring to the fact a lot of those 120V circuits are probably only protected by something like 12-15-20A of circuit breakers that might take a while to actually blow and unless you're in a kitchen or a bathroom or whatever probably don't have GFCI protection. Messing something up can quickly lead to quite a fire.
zevon
I would not want to touch 120V with wet hands, for example...
steve_adams_86
> You'll definitely need to learn to solder.
Probably implied here, but learning to desolder is huge too. And there are tricks to it that didn't come easily to me. When you buy your first iron, I think it's worth getting some flux and solder wick as well. Taking circuits apart cleanly and properly can make repairs so much easier.
baq
Me the complete soldering newbie was very surprised when he discovered that desoldering is much more difficult than soldering. Getting a blob of tin to conduct is easy, getting the blob of tin out of there… impossible without tools and technique. Obvious in hindsight.
tosmatos
On that note, is it worth it to get a desoldering iron ? Like, what is essentially a soldering iron and a desoldering pump combined ? I've had little success desoldering in the past, and broke boards because of it.
mtts
Yes. If you can afford it (around 100 $€ will get you a basic one) and you expect to use it more than once, it'll save you a lot of grief.
bombcar
Desoldering is one of those things where the right tool is almost mandatory.
Sure, you can desolder with a cigarette lighter and some luck, but you’ll be much happier with the iron.
7402
Gosh, you don't need to start with dangerous high voltage tube stuff! There are old transistor electronic devices that was built on circuit boards with nice discrete components. You can practice soldering and unsoldering on an old transistor radio.
kazinator
To debug electronics effectively, you cannot underestimate how much EE knowledge is needed.
Start with something like The Art of Electronics by Horowitz and Winfield.
An example of the kinds of EE stuff you don't heave to know to be an effective troubleshooter of basic issues, might be, oh, say, what it means for the poles of a transfer function lie in the left half of the s-plane.
bombcar
As a counter, you can get amazingly far with little to no EE knowledge - depending on your troubleshooting skills and how modular something is.
A stereo that loses the right channel unless you push on the board? Broken solder joint.
Visibly exploded caps? Bad caps.
Some basic understanding of electricity and current flow and the high-level concepts will help, but a detailed education is more for building your own than just repairing existing mass-produced setups.
(As an aside the electrical knowledge in a good ham radio study guide would be a great place to start - https://home.arrl.org/action/Store/Product-Details/productId... )
pyb
Agree that a foundation in EE is needed, however AoE is not a beginner book.
homieg33
Just yesterday I fixed a broken wireless N64 controller receiver with the help of ChatGPT. I tried looking for YouTube videos, but didn’t find the exact thing I needed, and since I’m such a newbie I needed a lot of hand holding.
Anyways, I took pictures of the components and described what I was seeing. It walked me through things really well and asked me to do tests and report back. It even told me how to use my specific multimeter after I took a picture of it. I ended up soldering a jumper cable from the console power supply line (not working) to the micro usb power line (working).
It actually works now and really saved me 30 bucks buying a new controller.
rahimnathwani
This is fascinating. Would you mind sharing the chat transcript?
lnsru
The thing is that one needs understanding of an electrical engineer to debug circuits one wants to repair. When you have understanding you can do some voltage measurements and try to identify faulty part. There is gazillion different parts now, that wasn’t the case 2 decades ago.
I know few people who repaired their washing machines just watching youtube videos. No skills and no knowledge. That’s the best error you can find - series error. All the appliances of the same manufacturer built in the 5 years will predictably fail and replacing 20 cent regulator revives the machine.
There are then random faults, that need deep knowledge and hours of debugging. They’re not economically viable to repair unless the machinery is very expensive. Good example is 400€ transistor replacement in €20k Tektronix probe.
Then there are things one shouldn’t touch - Tesla battery packs and open microwave ovens for example. Enough energy to kill or badly injure the unlucky hobbyists (in German): https://www.kosmo.at/tesla-akku-explodiert-mann-schwer-verle...
There are enough analog electronics to repair what requires deep analog design knowledge. Music instruments and radio equipment might fall into this category.
I would say, the repairs make no sense in the future that comes. With more and more electronics and programmable components the repairs are not economically viable. I am designing a motherboard with MPM54304 PMIC and a microprocessor. Both are programmed and without firmware sources and circuit diagram one will not able to recreate desired functionality. After product release I will organize workshop for my colleagues from service department and they will still come to me to discuss the repairs when some early faulty products will be send back by customers.
bombcar
Washers and dryers are probably one of the best places to start - if you have the ability to bring them home, you can find them laying literally for free.
80% of the problems are a single part or loose connector, and they’re big enough and common enough that they’re easy to work on and have lots of YouTube help available.
Then you can progress to working on the control boards themselves instead of just swapping them.
If you have a garage and will do this, I highly recommend the harbor freight lift table: https://www.harborfreight.com/500-lb-capacity-hydraulic-tabl...
Once you get into it you can actually make some coin, free washer, $10-50 in parts, sell for $100 when working.
reassembled
The Northwest Repair Discord server is pretty active with people sharing techniques, tips, technical info and gear advice. While NWR's YouTube channel is mainly focused on GPU repair, there's a lot of good knowledge in their vids, and in their Discord channels.
Bjartr
Head to Craigslist to buy broken electronics on the cheap and practice repairing them.
One upside to this approach is that as you improve it can pay for itself by reselling the fixed items.
toast0
I was going to say the same thing. The way to learn practical repair is to get broken things and try to fix them ... chances are most of them will get more broken, but as long as you're not spending much to get your test subjects, no big deal.
bombcar
A wonderful way to start is to get two identical objects that are dead in different ways.
You usually can combine them to make one working one - no need to even buy parts.
A few weeks trolling Facebook marketplace or Craigslist will often get you some that match.
iamflimflam1
There’s a great (and very entertaining) YouTube channel that really shows what’s possible with minimal knowledge and good troubleshooting skills.
Retr0id
YouTube. Pick any piece of consumer electronics and you'll find videos of people diagnosing and repairing it, at both hobbyist and pro-repair-shop level.
The Nintendo Switch Lite is a fun piece of hardware because they're cheap to buy used/broken and there are many opportunities for component-level repair.
Some great written info (specific to the switch) here:
cafp12
I am no expert, but I have to imagine it would be quite hard to learn electronic repair without learning some basic circuits.
I've learned a decent amount with some electronics adjacent hobbies, like 3d printing, diy sim racing stuff, mechanical keyboards. Mainly just copying things other people build. Enough that recently I was able to diagnose a broken transformer in an electronic theater chair power supply.
This channel is awesome:
In my country, 2 decades ago there are were plenty of people who knew the basics. Today, it feels like a lost art.
I would like to approach it as a hobby, not like electronic engineer level, but enough to debug problem and change components to a low level.
What is the pragmatic approach in this mission? I reckon it will be valuable in the future that comes.