Hi there. I have this amp for repair. The 15 rails needed to run Ic4&6 are missing. The zener diodes are fine. Dropper resistors R47,34,49,55,62,65,64,61 are heating up. I have already replaced ic4&6. Same problem.
ENZO, maybe you have seen this before? Any ideas?
Post the schematic.
Otherwise .... IC4/6 , R47 to 61, etc. mean nothing.
Do your homework: what's used for the +/-15V supply?
Dropping from higher rails through power resistors and regulating with Zeners?
Dedicated low voltage PSU further regulated with LM7x15?
A combination of both?
What do those rails feed?
In a metallic screechy voice: "com-pu-ter-needs-more-da-ta"
Juan Manuel Fahey
Thanx for all the replies guys. I managed to track the fault down.. It was the transconductance amplifier chip that was soft shorted, pulling the 15V rails down.
So it was the + - 15 "B" supply.
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