Look at the area around the driver transistors. Are there any solder bridges?
Clean all flux from the board and examine the area with a lighted magnifying glass.
Clean all flux from the board and examine the area with a lighted magnifying glass.
A possibility on Q217 I removed old bjt and am installing new one, think solder might have sucked together underneath and not been visible from above. Dont know if this would cause it though....BRB
I replaced it and am positive no bridge and same result.
Something I wanted to bring to your attention.....................
Q211 now that I know what terminal is what........................
Black probe on emitter red probe on collector 12.89 vdc
Black probe on emitter red probe on base 0.00 vdc
When I hole the black probe on emiiter and touch collector I hear a clicking or like something is shorting out, but very faint like a small component.
Do you think Q211 is shorted?
You can determine if Q211 is shorted by checking on ohms or diode check. I don't think it's shorted.
The problem seems to be in this area. Just to confirm... You still had DC on the output terminals when you removed Q213 from the circuit?
Confirm that R275 still reads 0.009.
What is the DC voltage across R274?
The problem seems to be in this area. Just to confirm... You still had DC on the output terminals when you removed Q213 from the circuit?
Confirm that R275 still reads 0.009.
What is the DC voltage across R274?
Q213 out of circuit DC remains on ouput terminal (YES)
Q211 black probe on emitter red probe on collector or base reads OL
Q211 diode check black probe emitter red probe on collector or base no beep reads OL
R275: 0.009 VDC
R274: 0.009 VDC
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Still wondering what the faint clicking could be when holding black probe on emitter and touching red probe on collector of Q211?
I think your right on the area where the problem is.
I have a punch 360a2 excellent working amp I found on my shelf we could use as a reference if we need to.
R260 reads ~2.122 ( In any position of the bias pot ) you can turn it all the way clockwise as well and nothing. Niether channel will bias but the other channel has no DC voltage and produces very clean loud audio but will not bias. Wierd huh?
Lift D204. Does that eliminate the DC?
If not, slide C226 off of its pads. Does that eliminate the DC?
If not, slide C226 off of its pads. Does that eliminate the DC?
So first lift D204, if no result slide C226 off as in having them both off at the same time?
Removed D204 amp has same issue
Removed C226 amp has same issue
Both removed no change same issue -21.46 VDC on bridging terminal
I dont know what is making the drains dump -21.46 VDC on bridging terminal.
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