So no discussion on possible causes is allowed. Dang it. I would have asked what's on the table for that module besides temporary PS fault, organic component failure, and user error. I wonder what happens when you run it with both modes active? Output power surge? Burnt components at the output? No. Just learn the amp Danielson. Your questions are just wild ass guesses. Just learn the amp.
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WT800C Meltdown
- Thread starter DrEvil
- Start date
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- amp repair eden wt800
That board has been fried to the point where I would ask myself if it is re-usable. I'm leaning on the no side.
No, as I said here:
WT800C Meltdown
The answer could be many or anything.
A lot of people could chime in on possible scenarios but without going through the amp, no one knows. You have/had the amp and you don't know.
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This sequence of events is pathetic from a safety point of view, let alone that of a user experiencing a malfunction.
First, there was reason for the bassist to stop playing to check if the amp felt hot. Maybe that was tone or volume degradation, smell, or visible smoke.
Next, a brilliant idea to remove the top to observe internals of a failing amp occurred to "see" what was happening, while the amp was still being played. This activity had lethal potential that only fool's luck prevented.
Every experienced musician that I know "powers down" at the first sign of amp failure, in hope of minimizing damage and saving the amp.
That the amp in question was so dangerously abused is likely why minimal explanation is being offered to one of the perpetrators of the deserved "melt down" folly.
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That is the same approach, and often the outcome, with aircraft crashes.
What about getting an engineer or repair specialist to remove the power amp components and run it as a DC-powered preamp? Most of the "fun" in that amp is in the preamp anyway. If something didn't manage to fly all the way back to the preamp and fry something there, that might be a good option, but you'd need someone who actually knows what they're doing to make it happen.
You opened the floor to advice from anybody, but looking and talking isn't going to help fix the amp.
One possible scenario is that you successfully replace all the parts that are currently broken, power up, and the replacements promptly break again, because something that's not obviously broken is the actual cause. Or multiple somethings. Or multiple somethings which individually test well but which in combination cause problems.
The people here who know electronics best tend to be conservative with their advice. I imagine in part because they've learned that openly speculating on problems leads to people getting angry at them when they guess wrong. Even if the guess was wrong because the asker had provided them bad, misleading, or inadequate information.
Yeah, not really certain what watching a circuit board accomplishes.
The amp was new to him, supposedly had been gone through by a competent tech before the sale and reported to be in tip top shape. He was just monitoring his new to him amp. He doesn't know the thermal parameters and said he thought it might have been running hot after some time playing it. Those heat sinks do get pretty damn hot under normal operation. Later when I was there, there was still a question of if the heat was normal. He played on it for 5 or 10 minutes with the cover off. There was normal sound and no obvious smoke. There was a hint of abnormal smell coming from a foam piece glued on to the undamaged sides heat sink. Then the fan kicked on and a few seconds later we saw the resistor fail and arc. Foolish? Maybe. Fool's luck that no one died? sure with hands in or very close to the amp. Didn't happen. Abused? Maybe unintentionally.
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agedhorse
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This is preposterous, but might end up being an exciting adventure.
No qualified tech would consider approaching it this way.
Don’t use braid on the PCB unless you want to create more damage. In fact, the act of depopulating the board is fairly risky in itself, that era is not terribly robust.
No qualified tech on the planet would recommend the "melt down" protocol, which is now mirrored in hostile response, apparently. And, defensive walkback/reframing changes nothing of the circumstances and catastrophic failure, no matter how wishfully spun.
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Walkback/reframing = filling in details you appear to have made assumptions about. Hostility from you aside I was hoping to keep this civil.
The OP may find more repair help elsewhere, like here:
Music Electronics Forum: Maintenance, Troubleshooting & Repair - Music Electronics Forum
diy Audio: Solid State
As far as the possibility of engaging biamp/bridged mode causing the failure, that doesn't strike me as something that is likely to cause transistor shorting. All bridged mode does is send an inverted version of the signal to the other channel. Using both at the same time might lead to feedback or some odd noises, but I doubt it would impact the output transistors.
Music Electronics Forum: Maintenance, Troubleshooting & Repair - Music Electronics Forum
diy Audio: Solid State
As far as the possibility of engaging biamp/bridged mode causing the failure, that doesn't strike me as something that is likely to cause transistor shorting. All bridged mode does is send an inverted version of the signal to the other channel. Using both at the same time might lead to feedback or some odd noises, but I doubt it would impact the output transistors.
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Geri O
Endorsing Artist, Mike Lull Guitars and Basses
I know everyone advising against the pursuit of the repairs by the OP means well. It’s the 100% correct advice. Ya’ll have this OP’s best interests (and maybe health) at heart. I know it.
But there comes a time (and that time is coming sooner as I get older) where I would simply tell the OP “Go for it. You’ve heard the advice from those that know, you didn’t like what you heard, and your reactions are only proving to demonstrate how much you like to argue. Fine. I wish you well” and not look back nor give it another thought.
There’s the guy that didn’t listen to my advice on using the old Crown power amps in Parallel Bridge mode. I told him once. He wound up with a very expensive amplifier repair bill.
There’s the guy that reconed his batch of blown 18” speakers with Gorilla glue. Never reconed speakers before. I said “Don’t” only once. I hear the speakers (12, I think) lasted 1/2 hour on the next show.
I could go on about other various episodes of folks asking for advice and not liking what they heard. These days, my preferred answer is “I’ve no idea”.
God Bless you guys that try and try repeatedly.
But there comes a time (and that time is coming sooner as I get older) where I would simply tell the OP “Go for it. You’ve heard the advice from those that know, you didn’t like what you heard, and your reactions are only proving to demonstrate how much you like to argue. Fine. I wish you well” and not look back nor give it another thought.
There’s the guy that didn’t listen to my advice on using the old Crown power amps in Parallel Bridge mode. I told him once. He wound up with a very expensive amplifier repair bill.
There’s the guy that reconed his batch of blown 18” speakers with Gorilla glue. Never reconed speakers before. I said “Don’t” only once. I hear the speakers (12, I think) lasted 1/2 hour on the next show.
I could go on about other various episodes of folks asking for advice and not liking what they heard. These days, my preferred answer is “I’ve no idea”.
God Bless you guys that try and try repeatedly.
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Truth. And in commenting anybody is opening the floor to responses, such is part of the circle of life. Thanks for bringing some perspective to this thread regarding information sharing. It's a fair point. I can admit that maybe I shouldn't be quick to think someone is being intentionally dismissive by not addressing specific points that I ask about.
Your specific points that you asked about simply can not be addressed in a forum without examining the piece in question, in person with the proper testing equipment at hand. Even then it may not be able to determine what started the cascade of failure. That might be the problem of getting a non-satisfying answer.
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Your memes are killing me DJ. In a good way. You kind of jumped the gun but feel free to use my image as you like.