Phase Linear 400 issue help!

There's the temp difference though. 465 is way high. Try some de-oxit on the pots. With the amp off de-oxit the pot and wirk it about 50 times.
 
I don't think the PS caps were completely discharged its dropped to 400mV left 100mV right
 
To check the pot, put one lead on the center lead and one on the side lead and actuate the pot and watch the resistance, it's a 5K pot. Then switch to the other outside lead and do the same.
 
laatsch55 said:
To check the pot, put one lead on the center lead and one on the side lead and actuate the pot and watch the resistance, it's a 5K pot. Then switch to the other outside lead and do the same.
Click to expand...

Those cheap pots are notorious for just failing outright...
 
after cleaning on one side I get 0k-5k and nothing on the other side on both pots. they where dirty. but still no change on the bias adjusting them
 
Looking at the back side of the board 2 of the connections on the pot are connected by a trace that side is showing the short. The pot seems to work with the meter but im getting no change in the bias. It doesn't make sense, I should get some change if the pot is working right?
 
Unless the bias transistors are some tired ol 3403's. Yes the middle and one outside lead on the pot are on the same trace. Check R19, should be a a 470 ohm resistor. See how close it is.
 
now that the PS caps are fully discharged I think, its showing .280 left and .080 right.
 
enoyes12 said:
huh. you just talked right over my head. NPN transistors?
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If it conducts with the base positive, the transistor is NPN

If it conducts with the emitter positive, the transistor is a PNP
 
OK, pretend your talking to a dummy and I'll see if I can keep up. Where are the transistors, I see them on the schematic but where are they in the case?
 
enoyes12 said:
OK, pretend your talking to a dummy and I'll see if I can keep up. Where are the transistors, I see them on the schematic but where are they in the case?
Click to expand...

See what you get on the 3 wires going to the back middle of the board. Brown is emitter, black is base and red is collector.
 
Gepetto said:
See what you get on the 3 wires going to the back middle of the board. Brown is emitter, black is base and red is collector.
Click to expand...

Those are the wires you showed in your earlier pictures. 2 sets of 3 wires right in the middle of the mold/spore patch :-)
 
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