This is a burned ground trace.
Does the amp play with the lamp?
Measure output DC before connecting speakers.
If there is a large output DC, don't connect speakers, other parts will be broken.
Measure R601 and R602 (1.5k). If they are broken, the display won't work.
Hugo
Does the amp play with the lamp?
Measure output DC before connecting speakers.
If there is a large output DC, don't connect speakers, other parts will be broken.
Measure R601 and R602 (1.5k). If they are broken, the display won't work.
Hugo
What voltage do you measure at collectors of Q1 and Q2 (output transistors) with respect to the white wire on the secundary of the transformer?
With lamp attached.
Hugo
With lamp attached.
Hugo
OK, so you do have + and -46V without the lamp and with the trace repaired.
Do you measure DC at the output, without lamp? How much, left and right channel?
Hugo
Do you measure DC at the output, without lamp? How much, left and right channel?
Hugo
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Completely follow the trace and measure every component that is connected to it, especially the diodes (D509, D510, D416,...), but also the resistors and capacitors.
Somewhere there has to be a shorted component.
Hugo
Somewhere there has to be a shorted component.
Hugo
I think you mean Q502?
So many deads...
2SK34 could be replaced with BF245 but is also hard to find...
This is of course DIY but I think you need to ask yourself if trying to fix this amp is worth it.
Most probably you will find more broken parts that are difficult to obtain or substitute.
There is also the display that needs fixing.
Just a thought...
Hugo