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previous: Erik Miller Ampeg SVT 3 Pro output has DC -- 1131217264

Knowing when to quit?

11/15/2005 3:51 AM
Erik Miller	Knowing when to quit? I've replaced Q7-Q14; R25, 32, 34, 35, 37, 40, 41, 42, and 43; Q2, 4, 5, and 6. The only active device on the output board that hasn't been replaced is Q3, because I could not find one. And except for the big MOSFETS, everything diode tested okay after I pulled it, including Q3. I've tested every diode on the board, and they all test good. It still puts a solid -55V DC across the output. I don't like giving up on any repair, especially now that I have a schematic, but I've run out of things to try, unless anyone has any further ideas.

11/15/2005 3:51 AM

Erik Miller

Knowing when to quit?

I've replaced Q7-Q14; R25, 32, 34, 35, 37, 40, 41, 42, and 43; Q2, 4, 5, and 6.

The only active device on the output board that hasn't been replaced is Q3, because I could not find one. And except for the big MOSFETS, everything diode tested okay after I pulled it, including Q3.

I've tested every diode on the board, and they all test good.

It still puts a solid -55V DC across the output.

I don't like giving up on any repair, especially now that I have a schematic, but I've run out of things to try, unless anyone has any further ideas.

Replies:

Enzo Well, there are resistors. ANy ope... -- 11/15/2005 5:45 PM
Rick Erickson If the output devices aren't shorte... -- 11/17/2005 1:28 PM