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Ask HN: How do I learn practical electronic repair?

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Re: Ask HN: How do I learn practical electronic repair?

#81

Post by luxcem »

mrheosuper wrote: post #75

I believe the best way to learn is getting your hand dirty. Take thing apart, try to understand how it works. Start with simple thing: A heater, a drill, etc. You won't learn much if you take apart complex gadget like smartphone. Also learn common failure mode: MLCC usually short itself, or old devices usually have dried out capacitor. For repairing equipment, you dont need high-end equipment from fluke or keysight.…

For someone that try to learn electronics this comments is really hard to understand. What's "common failure mode", "MLCC", "DMM"? What does "old devices usually have dried out capacitor" means?

Re: Ask HN: How do I learn practical electronic repair?

#82

Post by kjellsbells »

> the future that comes

...is carrying some baggage there. What you need to learn for, say, a severe economic depression is different from the useful skills to survive a repressive government.

If you look at the things people built in the 1930s, there was a lot of repurposing, make do and mend, etc, to get some basic function restored or working. Barbed wire telephones, that sort of thing. Kind of like the jugaad approach. Whereas surviving repression showed up as home brew radios, mimeograph machines made from cookie tins, etc. For electronics, maybe an understanding of circuits, how to desolder and resue chips, what the popular ones do, etc.? You wont be fixing the finer points of the surface mounted control board of your fancy miele washing machine, but you might at least get the drum to fill, spin, and drain.

Re: Ask HN: How do I learn practical electronic repair?

#83

Post by hyperdimension »

luxcem wrote: post #81
mrheosuper wrote: post #75

I believe the best way to learn is getting your hand dirty. Take thing apart, try to understand how it works. Start with simple thing: A heater, a drill, etc. You won't learn much if you take apart complex gadget like smartphone. Also learn common failure mode: MLCC usually short itself, or old devices usually have dried out capacitor. For repairing equipment, you dont need high-end equipment from fluke or keysight.…

For someone that try to learn electronics this comments is really hard to understand. What's "common failure mode", "MLCC", "DMM"? What does "old devices usually have dried out capacitor" means?

"common failure mode" = 'they break in a particular way a lot'

As Randy Fromm says, "the things that work the hardest fail the most"

Examples: MLCC (multi-layer ceramic capacitors) over time will often fail short.

Older devices with electrolytic capacitors (the large can-shaped things often situated by where the power input is) have a liquid electrolyte in them that evaporates (boils off?) over time. When it does, they lose their capacitance and the power supply stops being able to supply (good) power.

The point being, when something stops working, check these things first. It's like if your lawnmower dies on you, don't go pulling off the head to look at the piston. Check if there's gas in the tank first.

Finally, a DMM is a digital multimeter. This is your basic tool to measure voltage, current resistance, capacitance, et c.) You can't do much troubleshooting without one.

Hope this helps.

Re: Ask HN: How do I learn practical electronic repair?

#84

Post by bombcar »

lnsru wrote: post #76

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 c…

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.

Re: Ask HN: How do I learn practical electronic repair?

#85

Post by bombcar »

tosmatos wrote: post #72
steve_adams_86 wrote: post #48

Earlier quoted context omitted.

> 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.

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.

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.

Re: Ask HN: How do I learn practical electronic repair?

#86

Post by bombcar »

kazinator wrote: post #63

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.

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... )

Re: Ask HN: How do I learn practical electronic repair?

#87

Post by bombcar »

toast0 wrote: post #9
Bjartr wrote: post #5

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.

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.

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.

Re: Ask HN: How do I learn practical electronic repair?

#88

Post by cowboylowrez »

vel0city wrote: post #32
mikewarot wrote: post #6

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…

> 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 i…

yeah I just treat any higher voltage like I would a snake, I stay away haha.

Re: Ask HN: How do I learn practical electronic repair?

#90

Post by rahimnathwani »

homieg33 wrote: post #57

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 spe…

This is fascinating. Would you mind sharing the chat transcript?
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