Learning How To Fix Electronic Stuff

Factual Questions
1

I have always been one to fix things myself. There are some things that I not attempted but would like to try to learn.

What books would be a good place to start?

I would like to learn to repair electronic things like TV’s, amplifiers, circuit boards…

I had a welding machine stop working and I could not fix it. Took it in for repair and was told that it was the board; it will cost $400, but if I can wait about 10 weeks I can have my board fixed for just $60. Seems like it cannot be all that hard to fix those types of things - am I wrong?

Do different devices require much different knowledge, or is a board from a welding machine much like one from a strobe light or a VCR? - sure looks like most of the same stuff in/on those boards.

If this is closer to IMHO, move it and accept my apologies.

Thanks

2

It took me 2 years of high school electronics and 5 months of Navy training to become an electronic technician. And that was back in the 70’s when things were much less complicated. Learning to read schematics and how the different components are suppose to work is the hardest part. Recent technology has also made the electronics industry one of the biggest contributors to the throw away society that we have become. Why spend $100 to fix a VCR that quit working when you can buy a new (and probably better one) for less than the cost of repairing the unit.

If all you want to learn is basic electronics, there are books at your local library that show you what you need to know. If you want to learn to actually repair things, plan on a couple of years in a techical school. Those components on an electrical board may look the same but each has their own purpose. A 150 ohm resistor may resemble a 10 microfarad capacitor on a board but each serves a completely different purpose. Even with all the training I have, if something quits I will toss it and buy a new one.

3

It depends. Sometimes you open the thing up and find an obvious problem (e.g. burned resistor) that’s easy to fix. Other times, it’s hopeless.

There will probably be a lot of difference. As compared to the VCR, there’s no particular reason for the welding machine to use cutting-edge technology or miniature circuitry, both of which make repairs much more challenging. Welding machines are typically designed to last many years, and emphasize simple and robust construction down to the circuit board level.
A good middle ground between being at the mercy of repair shops and taking courses in electronic repair is to practice on surplus equipment until you trust yourself to be able to take a device apart, examine it for obvious problems that are easy to fix, and put it back together. This level of competence isn’t hard for a “handy” person to get. You’ll need to learn how to solder properly, and such things as the resistor color code (Google). It can help to find a friend who’s good with such things and can answer questions.

4

I do a lot of electronics repair as a quasi-hobby. (I’ve been selling some things I fix on eBay to pay for the next things to work on, and still have money left over to buy Christmas presents, new tires and such.) There’s a guy, Sam Goldwasser, that has put together an amazing web site of electronic repair info. It’s the “FAQ” for sci.electronics.repair. Check that out first. If you get stuck on something, you can post a query to s.e.r. and maybe someone will help. Sam himself replied to one of my queries. Be sure to provide all the info about the item.

If you Google, esp. Google groups, for your model number, you will frequently find that someone has already ran into that problem before and posted a fix.

If you are an absolute beginner, you need to start off learning all the basics. Components, basic circuits, some theory, etc. The more you know, the easier it will be.

My step-father ran a TV-Radio repair shop when I was a kid so there was always a lot of junkers around that I could fix up and use. I did take some electronics courses in high school but I am mainly self taught.

Stay away from “dangerous” electronics at first. Microwaves, TVs and CRT monitors all have the potential to kill you even when they are unplugged. VCRs and computers are a good way to start.

I repair a lot of VCRs (Betamaxes) and almost always they only need some cleaning and sometimes a few rubber parts that I get at a local electronics supply shop. The second most common problem is the power supply. A lot of time they are simple enough that they can be diagnosed and parts obtained at a regular supply shop. I rarely need to order something over the Net. (But I live in a large city.)

The next most common thing I repair are computers, more recently laptops. (There’s money in the latter.) For those, I rarely fix an individual component, although I’ve actually have done that several times. It’s swapping out boards and other big parts. For special laptop replacement parts, I buy off eBay. There’s always someone parting out a busted laptop. Might be a good place to look for your part. (Which is why the repair shop will take longer to get it cheaper. They’re waiting for it to appear on eBay.)

The best sources for junk to work on are thrift stores and garage sales. I can buy something at a garage sale for $3 and not worry about breaking it. But if I can get it to work and sell it on eBay for $150, that’s nice.

For me, there is just an amazing joy in taking something that just doesn’t work at all and bring it to life. I know how Dr. Frankenstein feels.

But always keep an eye on the bottom line. My current project is a Sony SL2400 Betamax that might bring in $150 on eBay. I’ve spent 3 or 4 hours on it so far. So it is really a “rewarding hobby” rather than an actual way to make money.

5

Blown & Injected

You can only really fix things where you can see the components, what you’re probably calling ‘circuit boards’. Lots of modern electronics are not fixable at component level, you’d need to swap a whole board.

There isn’t likely to be anything fixable in a modern TV. And the voltages can be a bit scary.

Amplifiers, yeah do-able. If you learn how to test transistors (like, get a transistor tester) amps usually die when a power tranny goes. Cheezy amps tend to be on one monster 20-pin package, if that’s dead it’s all over.

like Xema says, sometimes you open something up and you can see a blown component other times there are no clues. FWIW I’ve only ever managed to fix mechanical faults on VCRs. Electrically knackered ones always ended up being chucked.

Just learn some basics (what’s a: diode/capacitor/resistor, what the pins on a transistor are, how power supplies work) learn to solder and open up some broken devices and tinker.

6

Thanks for all the replies!

I am not trying to make money - a friend just paid $200 to have an old 25" TV fixed. I told him new 27" TV’s can be bought for less than that but he likes his big old consol. Like ftg, I get satisfaction in making things come to life.

I have gotten lucky a few times by finding a blown fuse inside of a component and I have done simple things like fixing a broken solder joint on a power supply jack on a board. I would like to kick it up a notch.

Looks like I should start with a book on schematics and about the components found in electric devices. I used to get a catalog called Linsday’s Electrical Books; there were some interesting titles, anybody heard of that catalog?

7

Yes you can learn to do or accomplish most anything you really want to.

That being said plan to spend all day every day for several years to learn all the ins and outs of the ultimate goal.

I have a friend of long standing who fell into a state of depression. His b.i.l. gave him a computer from work that had been taken out of service and replaced. He started with email and groups, corresponded on topics of mutual interest. Got to the point of contacting me. Some time later I gave him all my accumulation of computer surplus of programs, parts, etc. he started to learn by doing.

He is now trading, buying parts, selling computers, etc. via the web. Mostly low end machines for those just getting their first computer. Builds up anything to your specs.
troubleshoots, repairs, tutors first timers, etc.

All in about 3 1/2 years working at it full time in his basement. Learning by doing, trial and error, etc.

8

Yes you can learn to do or accomplish most anything you really want to.

That being said plan to spend all day every day for several years to learn all the ins and outs of the ultimate goal.

I have a friend of long standing who fell into a state of depression. His b.i.l. gave him a computer from work that had been taken out of service and replaced. He started with email and groups, corresponded on topics of mutual interest. Got to the point of contacting me. Some time later I gave him all my accumulation of computer surplus of programs, parts, etc. he started to learn by doing.

His background was in electrical supplies for commercial electrical contractors, and industril controls, not electronics. Had some kind of associate degree via correspondance course(s). This gave him a foundation to build on.

He is now trading, buying parts, selling computers, etc. via the web. Mostly low end machines for those just getting their first computer. Builds up anything to your specs.
troubleshoots, repairs, tutors first timers, etc.

All in about 3 1/2 years working at it full time in his basement. Learning by doing, trial and error, etc.

9

.
Yes. I’m a big fan of Lindsay. They are now on the web, although I have more fun looking through the (now consolidated) catalogue.

10

I now find myself in a similar situation to the OP. A friend of mie just had his TIG welder go down and has asked me to help him find data for it. So, Blown & Injected, did you find anything?

11

Whoa whoa…wait. How can a TV or microwave kill me even if it’s unplugged? This kinda scares me.
-M

12

I guess you haven’t seen The Ring.

13

I would imagine it has to do with capacitors in the equipment. [url=http://www.pcmech.com/show/tt/205/]This has to do with capacitors in PC’s, but it’s the same idea.

14

Ack!!! Teaches me to post while tired… Link

15

hammerbach I have not yet looked but I will look for Lindsday on the web. The welding machine problem I described was a problem I had about two years ago and just had repaired by the techs at Weld World.

The only parts to a TIG machine that I have been able to fix are the torch, the lines to and from the torch including the water cooling system, and the treadle.

My microwave has a capacitor in it the size of the start up cap on my heat pump! There are directions for discharging the device printed right on the side of the cap.

16

OK, then. For those curious about Lindsay books, here’s a
link. You won’t find anything about fixing a welder there, but lots of other interesting stuff.

17

Gee, how can one find out why microwaves are so dangerous? Perhaps by clicking on the flarkin link in my post! Geez.

So for those who have trouble looking stuff up online:
Go to the RepairFAQ web site.
Enter it.
Click on the microwave page.
See the all-caps “SAFETY” link? Click on that.

If you don’t know enough just to find out basic safety information on line, I strongly urge you to not try and fix electronics. You’ll end up killing yourself. Do-it-yourself means do-it-yourself for getting safety information too.

18

What’s the general opinion on the Forrest Mims books available at RadioShack?