I like repairing Analogue Electronics because ...

[Kilo Tango]

Quite often the faulty bit shows its self.

Its a Tek 465B with the dreaded arcing sound. I first thought I would need to pull the tube out, but a shield underneath labelled “ high voltage” was the clue. A pretty arc from one of the 2450V smoothing caps. It works fine with it removed, but I found replacements easily enough. They are only 5KV rated, small stuff !!!.

Ken

[bd139]

That's a nice easy one fortunately. The same is not the case when you get a slight performance degradation which is what I have on both my 465B and 475 units. Also if it's the HV multiplier, enjoy getting that out and replacing it. Have to take the interface board out which is one of those jobs I just don't want to have to deal with. You can see the two mounting nuts for it in your picture

Make sure you clean all the black crud off everything when you replace it with some IPA or something - it can arc out to that as well.

[Kilo Tango]

Yes I know what you mean. I also have an old tek 422 that works fine except the trace is fat. Its as if the triggering is jittering and so traces are landing slightly delayed or advanced over. Yet scoping the trigger signal it looks absolutely rock solid, no jitter at all. That will keep me busy for a while !.

Ken

[bd139]

Tek 422 is a nice piece of kit. Post some pictures if you crack it open

Keep failing to win them on ebay

[Samogon]

Or it can be rephrased - i like repair analog electronics because i dont know how to deal with digital.
 

[Kilo Tango]

Digital can be a real pain sometimes. I used to (try to ) repair a small control board that comprised 6 Lattice FPGA's, that ran very hot normally. They would sometimes start behaving strangely, and it was a guess as to what was wrong. Of course the bloke who wrote the code, (on a compaq laptop that was new when he did) had long since left the company, so there was no one to work out how these damn things worked, or didn't.

At least if it blows there is generally a hole in the top !.

Ken

[Samogon]

Agree, didital systems has higher density and complex behavior. And if you facing software loss like micro controller with mask rom inside, You almost screwed.
And failures are not so obvious like in analog devices.

[vk6zgo]

Agree, didital systems has higher density and complex behavior. And if you facing software loss like micro controller with mask rom inside, You almost screwed.
And failures are not so obvious like in analog devices.

Have you repaired much analog stuff?
Subtle faults in analog equipment are more the rule than the exception.

[Samogon]

Agree, didital systems has higher density and complex behavior. And if you facing software loss like micro controller with mask rom inside, You almost screwed.
And failures are not so obvious like in analog devices.

Have you repaired much analog stuff?
Subtle faults in analog equipment are more the rule than the exception.

Not much, nowadays electronics in most cases hybrid of digital and analog parts, like transceivers for
Instance even they have tendency to become mostly digital.

[Kilo Tango]

In general electronics tends to last a very long time, if it has been designed properly.

I use to repair control boards and displays that were made in 2000, a mix of analogue channels and digital processing, generally the faults were components being shaken off the board or a certain CAN driver used to fail occasionally. Not bad for 17 years 24/7 operation.

Ken

[Rasz]

I like repairing Analogue Electronics because:
-Im so old Iv been to the 1893 world fair and met Tesla in person
-dont like learning new things
-get off my lawn

did I miss anything?

[bd139]

Everything is analogue under all the abstractions

[Mjolinor]

Everything is analogue under all the abstractions

Actually it's digital under all the abstractions. The test gear gets expensive though when you start talking quantum voltage levels.

[Cyberdragon]

I like repairing Analogue Electronics because:
-Im so old Iv been to the 1893 world fair and met Tesla in person
-dont like learning new things
-get off my lawn

did I miss anything?

The fact that I'm 21 and repair tube circuits...

[Rasz]

I like repairing Analogue Electronics because:
-Im so old Iv been to the 1893 world fair and met Tesla in person
-dont like learning new things
-get off my lawn

did I miss anything?

The fact that I'm 21 and repair tube circuits...

oh yeah, forgot one indeed
-hipster
thanks

[Specmaster]

I like it because the parts are so much bigger for a start and if you have big hands and poor eyesight thats a real bonus 

Also of course the circuit is a little bit easier to trace out and the parts are normally clearly labelled with their part numbers, modern SMD sucks because its the opposite of the above in every sense.

[Electro Detective]

I like to repair analog electronics because i don't know, or want to know, how to deal with obvious digital throwaways and their bugs.

I don't need or want a retool or cumbersome microscope rig to play with and hog bench space 

There's NO MONEY in it   

More 'because' to follow, watch this space...   

[Armadillo]

I like it because it is the easiest and cheapest to repair, it's plain old vanilla, without digital, no scrambling, no encoding hence no need decoding, no secret keying, at most its inverted, that's it.

No need to know all those protocols. No need to buy all those interfaces, debuggers, emulators, programmers. Save a lot of money.

One Channel we call it mono, Two Channels we call it stereo, things are that simple, no bits, bytes, words, floating points etc... hence single sided circuit board is easy to trace.

No need to use microscope and don't even need to wear a loupe, no need bright lighting, candle light will do.

Even if one day my soldering hands vibrate to a span of +/- 10mm, it will still be right for the job.   

[flowib]

You're not alone, I'm 22 and got more boatanchors then i can count...  Nicest is perhaps my tek 585A.

Analog is by no means a forgotten art, however the curriculum for EE students has in my opinion moved too far away from analog circuitry, its all software and signal processing theorem atm.

[bd139]

It was like that when I went to university. First lab was building a successive approximation ADC. Second lab was Pascal. Third lab was poking VHDL.

Lecturers were like: Transistors, in 1994!?!?!? Those dirty cheap legged whores can be replaced by a £20 Linear opamp don't you know!!!! Want to turn something on and off? Buy a Darlington IC and behold the pin count!!!!! 

[Specmaster]

It was like that when I went to university. First lab was building a successive approximation ADC. Second lab was Pascal. Third lab was poking VHDL.

Lecturers were like: Transistors, in 1994!?!?!? Those dirty cheap legged whores can be replaced by a £20 Linear opamp don't you know!!!! Want to turn something on and off? Buy a Darlington IC and behold the pin count!!!!! 

And thats what they call progress, basically building a lot of good useful stuff but when it goes wrong, throw it away and buy another with all the pollution that all of that entails, never mind global warming' lets just keep churning out parts because the factories want them even more with builtin obsolescence   

[Kilo Tango]

Yes it gets a bit wasteful of stuff.

I got a faulty 28" Cello TV that was being chucked out and the fault was the soldered joint on the DC connector had broken down. If they had used lead solder, it would have filleted the joint so been a lot stronger mechanically and would have lasted.

The push is to "buy new electronic stuff" when the old stuff is still working fine, where will it end ?.

Ken

[bd139]

I'm doing ok out of fixing stuff headed for landfill so I'm not complaining

Last year was the best win. Dead Samsung 40" OLED TV, about £500 retail. Buyer listed on ebay "Dead. Makes burning smell when turned on" and "buyer collects only" with 85% positive feedback which is pretty shit. So low risk as I could see if it was nicked or the guy was an idiot first, put a £50 bid in and won it for £0.99. One capacitor later and it's sorted ... total expenditure £2.20 and a 5 minute drive. And the £2.20 was only because RS only sold the damn capacitors in packs of 5.

He nearly cried when I said he could keep the change from the £1 coin I gave him 

Got receipts as well for it. You know the stupid thing? He had no idea that it was still warranty returnable after a year.

[Specmaster]

Yeh, I keep hoping that I'm going to find something like that but all the things I go after, everyone else decides that they want it as well and it ends up in a bidding war and either I decide that I'm pulling out or I get the bit between my teeth and keep going and end up paying more than I really wanted to  Other times I watch it and decide that I'll bid on it at the last minute and normally one of two things happen, either the seller pulls it from the sale, or I forget to bid and it never sells 

[bd139]

Yeah that's a killer too. Been there a few times.

The winning formula for a seller is:

1. Low feedback
2. A least one negative
3. Unsociable hours listing
4. Doesn't know what it is.
5. Can't spell
6. General dumbass (fortunately we live in the UK so there's plenty of them!)
7. Collection only.

I'll always set alarms for when they finish