Any Electronics Enthusiasts?

[Vincenzo Corleone]

When I was a kid, I used to take broken electronic things apart and mess around with the electronics on the PCB. I learned to solder and to use a de-soldering wick to remove components from the board and then solder them back. I learned how to identify the various electronic components. I don't recall doing anything sophisticated, just learned stuff here and there.

Anyway - I thought it would be neat if, instead of replacing various electronic devices that break, I could just identify the bad electronic component(s), swap out a bad capacitor or transistor, and fix the problem. I'm pretty good with solder and a soldering gun. At the moment, I have an alarm clock, the display on which doesn't work that I'd love to be able to fix.

If I'm not mistaken, in order to identify bad components, I'd need a multimeter. Is that right? I never used one before but have seen YouTube videos and it doesn't look like rocket science. Any multimeter recommendations? Anything else I need to be aware of if I want to pursue this?

 

[f35phixer]

Spent many years doing I level maintenance on F18 circuit boards. T/S down to component level was great challenge. Almost every board was a different problem…

 

[ERD50]

I've been happy with this.

https://www.amazon.com/Tekpower-TP2844R-Auto-ranging-Multimeter-Resolution/dp/B004YF0VEM

Later, I bought a clamp-on ammeter, so I could measure current w/o needing to break open the circuit (though you need *one* lead isolated to get a measurement).

https://www.amazon.com/UNI-T-Digital-Handheld-Resistance-Capacitance/dp/B0188WD1NE

Many products are so integrated now, that troubleshooting can be a real challenge. But often, it's a loose connection, and those can often be found visually (a magnifier helps).

-ERD50

 

[daver]

A schematic diagram of the circuit would help if available...

 

[ncbill]

I've been happy with this.

https://www.amazon.com/Tekpower-TP2844R-Auto-ranging-Multimeter-Resolution/dp/B004YF0VEM

Later, I bought a clamp-on ammeter, so I could measure current w/o needing to break open the circuit (though you need *one* lead isolated to get a measurement).

https://www.amazon.com/UNI-T-Digital-Handheld-Resistance-Capacitance/dp/B0188WD1NE

Many products are so integrated now, that troubleshooting can be a real challenge. But often, it's a loose connection, and those can often be found visually (a magnifier helps).

-ERD50

Bad capacitors are notorious on appliances (e.g. oven, range, microwave) displays.

Replace just those and you can usually read your display again!

 

[isisdave]

You can get a decent multimeter for 6.99 at Harbor Freight, and a pretty darn good one for $20 lots of places.

Stuff isn't as repairable as it used to be though. There is a lot of Surface Mount Technology that can't be removed, and is so small it's even hard to test.

What might be of interest to you now though is microprocessors -- Raspberry Pi and Arduino and their cousins. There are lots of development kits etc. and they're fun to play around with.

 

[ERD50]

You can get a decent multimeter for 6.99 at Harbor Freight, and a pretty darn good one for $20 lots of places. ....

I gave up on those cheap meters. The selector switches have a tendency to get intermittent, and dealing with a flaky meter while troubleshooting (especially an intermittent problem!) is beyond frustrating. The $35 one I listed below has been good for me. $20 will probably get you reliable one, if you search carefully and read reviews critically.

... Stuff isn't as repairable as it used to be though. There is a lot of Surface Mount Technology that can't be removed, and is so small it's even hard to test. ...

True. And my eyes aren't as good as they used to be either!

... What might be of interest to you now though is microprocessors -- Raspberry Pi and Arduino and their cousins. There are lots of development kits etc. and they're fun to play around with.

I've been doing a few projects with these Arduino micro-controllers. It's amazing what you can do with a cheap controller, and add display board with switches, and you've got some user interface with very little work. I like this, as it has the LED 7-seg display with switches and LEDs. About $12 for 3 with (slow) shipping:

https://www.ebay.com/itm/183425727496

And this micro-controller, has gone up to ~ $10 each, I think I used to get 2 or 3 of them for that:

https://www.ebay.com/itm/284475378554

-ERD50

 

[OldShooter]

You can get a decent multimeter for 6.99 at Harbor Freight ...

Noooo..... Do not buy cheap tools!

I gave up on those cheap meters. ...

What he said.

A Simpson 260 Is a top quality old-school analog multimeter. A Triplett 310 is another, somewhat smaller. Both are readily available both new and used. They have been manufactured for a half-century that I know of, maybe longer. That says something about quality and utility.

I have had very good luck with Tenma products as well. https://www.newark.com/c/test-measurement/multimeters-clamp-meters?brand=tenma The Tenma multimeter I have came with slip-over rubber armor incorporating a tilt stand. Very nice product. IIRC around $50.

Regardless of equipment, @Vincenzo, take @daver's advice and start your electronic journey with an item where you can get a schematic diagram.

 

[Freedom56]

The easiest failed component to identify, remove, and replace is a relay. They usually burn out and are also the most common component that fails. As for tools, a multimeter is a start but you also need a temperature controlled soldering iron and wicks. If you plan to do any real trouble shooting, you will need a scope.

 

[Time2]

Yes, been in electronic repair since HS, when I got a job at a video sales and service company. Started, by replacing the capacitors in old black and white monitors used in factory surveillance systems. Gradually moved to 1/2" reel to reel video recorders/players then 3/4" cassette tapes, (U-matic). Then did a stint repairing automobile test equipment, Spent a couple years in an electric motor repair shop, then 4 or 5 years building and repairing geophysical test equipment. I spent 10 years repairing VCRs and another 7 years building and repairing ultrasonic test equipment. Then I spent 18 years selling shrimp at a marina, huh?
I have almost always had a bench setup at my home to tinker on. I have laid out and etched PCBs for mostly radio antenna preamps.
To answer your question, yes, I'm an enthusiast!
Here's my bench. If I'd known you were asking, I would have cleaned it

 

[Animorph]

I'll go with the big electrolytic capacitors in power supplies as the most common failures. They're usually easy to identify by the top puffing out a bit. And they're still big enough to unsolder and resolder without special tiny equipment. I've fixed lots of equipment that way. I use a manual vacuum desoldering tool, never being very good with a wick.

I've replaced a few relays, also quite doable, but I don't have that many devices with relays.

Simple loose connections, bad solder joints, and broken wires are my last main fixable category. A magnifying glass can come in handy for identifying those.

Beyond that I figure it's more trouble than it's worth to replace anything smaller. And if it's a wall-wart power supply, I'm more likely to just buy a new one.

 

[NW-Bound]

^^^ Hey, I see an HP signal generator and a Tek scope.

I have 3 HP signal generators, 2 HP spectrum analyzers, and 2 Tek scopes. My best generator is digitally synthesized to 3.2 GHz. The digitally tuned analyzer goes up to 2.9 GHz, while the analog one goes to 42 GHz via harmonic mixing (I have never gone that high). My better Tek scope is 500MHz. I also have half a dozen power supplies, and miscellaneous pieces of equipment.

But back on what the OP says, it is hard to repair modern electronics, or even troubleshoot them. They are all choked with custom ICs, and even if you know which one is bad there's no way to buy replacement parts. Replacing surface-mounted ICs is like conducting surgery.

Nope, cannot repair much anymore, or even locate the failure, unless the problem is a really simple one.

But you can still build a lot of stuff with the components you can order from the Web.

 

[Time2]

^^^ Hey, I see an HP signal generator and a Tek scope.

I have 3 HP signal generators, 2 HP spectrum analyzers, and 2 Tek scopes. My best generator is digitally synthesized to 3.2 GHz. The digitally tuned analyzer goes up to 2.9 GHz, while the analog one goes to 42 GHz

Yes, I have a HP8640B, and HP651B sig/gens and a Tek 2465 scope. Several Boonton 92EA RF meters and a Boonton 260A Q meter, I have had a lot of fun testing high Q coils made for crystal radios. Qs up to 1400.
Hmm, 42MHz is in the realm of magic, and I'm not a magician.

But you can still build a lot of stuff with the components you can order from the Web.

Yep, I'm the process of putting together a Low noise, high gain, mic/preamp/amp system for a parabolic or shotgun type microphone. I did make one preamp pcb, that worked with an adjustable max gain of 3500! See the Altoids container, and the other is a Norton RF amp I etched and built many years ago.

I did order several different low noise preamp pcbs from Aliexpress to experiment with, just want the one with the lowest noise. I don't have knowledge or the math skills to start from scratch and get low noise.

 

[NW-Bound]

Yes, one of my 3 HP generators is an HP8640B. This generator has very low phase noise from its tuned cavity design, and to this day is still a useful piece of equipment.


PS. I used to spend hours studying the schematic diagrams of HP and Tektronix equipment. They were designed by the masters of electronic circuits.

 

[conversationalphrase]

8640B is one of the cleanest generators ever made! It was the gold standard for radio development for a long time.

 

[Vincenzo Corleone]

I have the alarm clock PCB in front of me and I see what people are saying about the surface mounted components. That does put a kibosh on my plans. Oh well. In search of another hobby...and a new alarm clock.

 

[mountainsoft]

it is hard to repair modern electronics, or even troubleshoot them. They are all choked with custom ICs, and even if you know which one is bad there's no way to buy replacement parts. Replacing surface-mounted ICs is like conducting surgery.

Nope, cannot repair much anymore, or even locate the failure, unless the problem is a really simple one.

But you can still build a lot of stuff with the components you can order from the Web.

When I was younger I loved to fix electronic items and build a variety of odd gadgets. I remember adding a speech synthesizer chip to my first computer, fun stuff. My bedroom was filled with cabinets of transistors, resistors, and capacitors. Radio Shack was my favorite store. My favorite book was the Master IC Cookbook and I had electronics magazines all over the place. Most kids had posters of girls or cars on their walls, I had pictures of clock radios and stereo equipment. Yeah, I was a nerd.

I went to college to study electronics, hoping to make a living repairing electronic items. Unfortunately, even back in the early 80's things were already transitioning from fixing to replacing. Repairs were generally limited to replacing entire modules. For a short time I worked in a small shop repairing things like answering machines, radios, and digital clocks, then ended up repairing microwave ovens for a few years.

Eventually I just lost my interest in electronics. Except for a couple of multi-meters and soldering irons, I threw out all of my electronics parts in the late 80's. I can still fix simple stuff like broken wires or an obviously bad component, but for the most part I don't even remember how most of the electronics stuff even works anymore. If it breaks, I just buy a new one.

Along the way I discovered writing computer code gave me the same thrill as tinkering with all those electronic parts, so that's what I've been doing the last 30 years or so.

 

[Time2]

Unfortunately, even back in the early 80's things were already transitioning from fixing to replacing. Repairs were generally limited to replacing entire modules.

Yes, the declining cost of electronics is what ended my time repairing VCRs.
I started VCR repair in 1984 when a VCR cost $600, making them well worth repairing, but when I quit repairing VCRs in 1995 you could get one for $69.
A few years ago I returned to visit the shop I worked at, when I left there were 5 techs doing repairs on various consumer items. There was only the owner left doing Large screen TV repairs, and that was all board replacement repairs.

 

[Car-Guy]

I do some electronics component level testing and replacement. Things like resistors, (need to know your color codes) capacitors (need to know your values and watch + and - connections, various relays, etc... Not so much "chips"... Yes a good multi-meter with various probes and clips and a good low wattage soldering iron are the basic tools... That and a large hammer (for those things that I can't fix) works for me.

 

[Sunset]

Yes, the declining cost of electronics is what ended my time repairing VCRs.
I started VCR repair in 1984 when a VCR cost $600, making them well worth repairing, but when I quit repairing VCRs in 1995 you could get one for $69.
A few years ago I returned to visit the shop I worked at, when I left there were 5 techs doing repairs on various consumer items. There was only the owner left doing Large screen TV repairs, and that was all board replacement repairs.

My first VCR cost $1,000 , it was when the choice was that or those LP record sized laser disk players.
I must have been crazy at the time as $1,000 was a huge amount of money at the time, probably more than my SWR currently.

Years later I repaired it by replacing some of the elastic bands inside, as it was too valuable to throw away.

 

[finnski1]

My first VCR cost $1,000 , it was when the choice was that or those LP record sized laser disk players.
I must have been crazy at the time as $1,000 was a huge amount of money at the time, probably more than my SWR currently.

Years later I repaired it by replacing some of the elastic bands inside, as it was too valuable to throw away.

Yeah I paid $2100 for a tube tv about 20 years ago Thought it would last forever

 

[NW-Bound]

My first VCR cost $1,000 , it was when the choice was that or those LP record sized laser disk players.
I must have been crazy at the time as $1,000 was a huge amount of money at the time, probably more than my SWR currently.

Years later I repaired it by replacing some of the elastic bands inside, as it was too valuable to throw away.

I must have bought after you did, because I only paid $750, in 81 or so.

And I paid $1200 for a shoulder camcorder in 1985.

 

[easysurfer]

When I was a kid, I used to take broken electronic things apart and mess around with the electronics on the PCB. I learned to solder and to use a de-soldering wick to remove components from the board and then solder them back. I learned how to identify the various electronic components. I don't recall doing anything sophisticated, just learned stuff here and there.

Anyway - I thought it would be neat if, instead of replacing various electronic devices that break, I could just identify the bad electronic component(s), swap out a bad capacitor or transistor, and fix the problem. I'm pretty good with solder and a soldering gun. At the moment, I have an alarm clock, the display on which doesn't work that I'd love to be able to fix.

If I'm not mistaken, in order to identify bad components, I'd need a multimeter. Is that right? I never used one before but have seen YouTube videos and it doesn't look like rocket science. Any multimeter recommendations? Anything else I need to be aware of if I want to pursue this?

I'm pretty much in the same category as you. Wish I was more knowledgeable and skillful with electronics but not so. I do own a multimeter, capacitor tester and soldering station along with a desoldering gun. The biggest fix I made was having the replace some blown capacitors on a computer's motherboard. Other than that, only replaces stuff like a burnt out LED bulb on a garage remote control and portable computer speaker.

 

[Time2]

My first VCR cost $1,000 , it was when the choice was that or those LP record sized laser disk players.
I must have been crazy at the time as $1,000 was a huge amount of money at the time, probably more than my SWR currently.

Years later I repaired it by replacing some of the elastic bands inside, as it was too valuable to throw away.

Our first vcr was $1,032, had all the bells and whistles including Hi FI audio, that I never made good use of. It was only a few months later that my wife's nephew bought the same VCR for $200 less. Hurmph! Ya, that was a stupid purchase as we only earned about $22k back then.

 

[Qs Laptop]

i do some electronics component level testing and replacement. Things like resistors, (need to know your color codes)

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