• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join freeLog in
    Want zero display ads or expanded classifieds tools? Compare plans.

Power Amp Repair Question

Bivwack

Guest
Aug 5, 2012
8
1
#notanelectrician

I decided to see if I could figure out how to repair my Carvin BX1500 head. Channel #1 is giving my a lot of static and cuttin in and out, and channel #2 has no output at all.

I noticed some white powder spilling out from under one of the heat sinks. I decided to pop them off, and I find what appears to be a handful of failed material and/or components (see pic).
20181229_141059.jpg

Anyone know what the pink colored material is? The same components that are covered in the white stuff are also beneath the pink material. It looks to me like the link stuff is meant to help transfer heat from the components to the sinks, and when they fail, they turn into white chalky / power stuff... And if I had to guess, I would bet the sink that had 100% white stuff beneath it was associated to channel #2, which doesn't work at all.

Any ideas? Am I on the right trail?
 
#notanelectrician

Any ideas? Am I on the right trail?

I would say no. Some/many/most technicians won't touch this knowing that you attempted a fix on your own. Do you own a variac? If not, please get one. You should not connect this amp directly to a 110-120 volt AC power receptacle, no matter how cautious you might be. If you do, please make a video and leave a note.
 
I don't think you are on the right track.

That's a class D amp with little heat being generated compared with a linear amp.

When these fail, it's almost always an electronic failure that rarely shows any visual indication.

These problems are difficult to repair even for an experienced tech. Since Carvin is no longer supporting their products, it's pretty much valueless anyway.
 
I really, really wish you had posted before you botched your amp. there are some tricks with Carvin gear that can possibly sort out the problems you mention. Not so likely now! :rollno:
Fortunately, it wasn't the DIY home brain surgery kit he was working on...
 
  • Like
Reactions: BassmanPaul