Help. I blew up my amps...

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First let me say that the longer I read here the more I learn. Thanks to all you folks for the resource.

Anyway, awhile back I toasted two UCD180's by putting power to the outputs. I reversed the orientation of the boards and spaced out as I reconnected their existing harness. Power on - POP - smoke - a silent, imagined, tiny electronic scream as sudden death ensued...

+/- power connected to +/- speaker.

I blew the top off the cap labelled A in the picture - nuttin left but two metal leads and a plastic base.

Whatever it was inside that cap was spattered everywhere. It looked like tiny shreds of fibreglass.

Both amps blew the same cap - that is - on the right of the heatsink as shown in the picture. They did not blow the identical cap on the other side of the heat sink.

I am just a hobbyist wrt audio hardware and I'd be obliged if you could help me answer a couple of questions.

1). what did I blow up and what does it do?

2). Is it possible that that cap is all I blew?

3). Shall I solder it out and replace it just for grins, or is it hopeless?

4). If it isn't hopeless could someone tell me how I can specify a replacement? Kevin sent me to Digikey (for a 22MFD 63v cap) but the choices are mind-boggling. There's a bunch of different ones. Which one is right?

Jeez, I know all this sounds really lame but I'm honestly enjoying this and want to learn more.

Hey, at worst, I have a new career making smoke-bombs! (LOL)

Best Regards,
Tom
 

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1). what did I blow up and what does it do?

2). Is it possible that that cap is all I blew?

3). Shall I solder it out and replace it just for grins, or is it hopeless?

4). If it isn't hopeless could someone tell me how I can specify a replacement? Kevin sent me to Digikey (for a 22MFD 63v cap) but the choices are mind-boggling. There's a bunch of different ones. Which one is right?

1-It's a high ESR electrolytic bypass cap used for snubbing the power rails.

2- Unlikely, since it's just a decoupling cap it would still work without it if nothing else was blown. Check for blackened components as a first step.

3. Hard to say, proceed with caution.

4. Look for other burnt components first.
 
classd4sure : Thanks for your answer :

On a close inspection of the board (top and bottom) I find no evidence of toasting - no flux runs - and no discoloration of components. It doesn't smell like burnt pcb either...

Would work without it? Hmmm. I didn't even try to run it after the pop. I powered down soooo fast.

:confused: Maybe a good meatball test would be to hook it up to my power supply and see if it works before ordering the caps? :confused: Might tell me if anything else if cooked. Unless it might fry the power supply? :eek:


bwrx :

Thanks for the ID on the cap and the heads-up on where to find it. Not to worry about finding it for me tho, I've got to learn this some time. Why not now? ;)

Thanks both.

Best regards,
Tom
 
Tom:
After you solve this you may want to buy a variac for test purposes. I bought one, second hand, cheap... it surelly helped me many times as its fuse is the first to blow when things go wrong. ;)
Unless this will be your last DIY project wich I doubt :) as this hobby is like a disease: a success leds you to another project and a frustrated one makes you hungry for revenge! :devilr:

Good luck!!!
M
 
Thanx Max...

No, it certainly won't be the last - no antibiotic can cure me now!

I'd have to learn how to use the test equipment before I'd benefit, but hey, I'm willing.

It's hard to start off in this thing - so much to know - and too much to learn right off the bat.

I'm patient - what the hell - I might live another twenty years and get a shot at knowing what I'm talking about!

LOL

:D

Best Regards,
Tom
 
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