When caps go bad...

[eldanko]

Back in college I had a Cambridge Soundworks 2.1 speaker system that was, on all accounts, the best sounding computer speaker system I've ever heard. After a few years of use, it eventually wouldn't power up correctly or wouldn't remain on long enough to be useful, so I put the sub in storage and used the satellite speakers elsewhere.

Having successfully repaired one of our TVs last month with some of the knowledge I've gained from the pedal game, I decided to pull the sub out and try to fix it. After surveying the inside, I found two power supply caps that were bulging and ordered replacements from Mouser. I soldered them in yesterday and - what do you know - good as new. Never sounded better.

...until tonight. I had just started to play some music on them (probably only the third time I've turned them on since the repair) when they powered themselves down abruptly. I opened the sub up and a generous amount of smoke poured out. It would seem I overlooked a third problematic capacitor, a smaller 63V 470uF, that decided it was through with life and that it would take most of the circuit board down with it. At least, that particular part appeared to be ground zero for the small explosion inside the amp.

[Gledison]

Maybe is time to bury it
or you still can save the board?

[alanp]

If it's still a good sounding amp, go for it!

I think my Kenwood amp has a cold solder or something, but it only comes up once a week so I'm not worried.

[eldanko]

I'll have to scrape off some of the burnt areas and see the extent of the damage. I think the board itself is actually charred around those two little holes you see in the picture. It may be time to say goodbye 

[rullywowr]

Nothing quite letting the magic white smoke out of a capacitor!  Hope it pulls through man.  I have a Samsung TV that has a cap issue and randomly powers on and off...debating whether to have them fix it under warranty (maybe) or tackle it myself.

[eldanko]

Funny, the TV I repaired was a Samsung as well. Evidently they chose to use underrated caps voltage-wise in the power sections of several of their models. Look for swollen filter caps. In fact, I ended up ordering more than I needed. Let me know which ones you end up needing and I can shoot some to you.

[gtr2]

Samsungs are notoriously bad with the caps on some of the models.

The funny thing is I have a panasonic plasma and it doesn't have panasonic caps    I had to fix it after a power surge a few years ago.

Josh

[rullywowr]

Funny, the TV I repaired was a Samsung as well. Evidently they chose to use underrated caps voltage-wise in the power sections of several of their models. Look for swollen filter caps. In fact, I ended up ordering more than I needed. Let me know which ones you end up needing and I can shoot some to you.

Thanks man!  I have to get the motivation to pop the cover off and see whats about to burst.  It usually power cycles once every two days while watching for now.