Help. I blew up my amps...

[ptwining]

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

[classd4sure]

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.

[BWRX]

http://www.vishay.com/docs/28312/036rsp.pdf

The cap is a BC components 036 series 22uF 63V. Digi-key doesn't have that specific cap.

Mouser might have it, I don't feel like trying to search through their mess for you though

[ptwining]

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.

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


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

[maxlorenz]

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!

Good luck!!!
M

[ptwining]

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



Best Regards,
Tom