I have my neighbors Pioneer GM-D9605, out of his truck, Local shops could not find why the truck battery going dead. He replaced this amp, problem solved. Now we wish to repair this old amp, any one have thoughts on what to look for. i have service manual, good documentation, been few years but i used to work all kinds audio equipment. I am one of them old fart techs dumb enough to take on any job. First look at the amp i see no problems, all components look good, no obvious defects. As i read the service manual this amp should draw almost zero current when idle. Any suggestions much appreciated.
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Q701 on the power section of the schematic is possibly the place to start - that should be fully off for standby mode, as well as Q714 (auto on). They drive Q702 which turns on the 12V power for the main power supply oscillator chip outputs. Perhaps these aren't fully turning off?
Yes the service manual says the power draw in standby should be 1mA (the one spec not in the user manual).
Yes the service manual says the power draw in standby should be 1mA (the one spec not in the user manual).
Could be dirty switch, had that happen on a calculator where the tracks were worked by a piece of plastic holding copper bridge.
Cleaned the gap between tracks, it was forming a resistor, problem solved.
The repeated working of the switch had formed a thin layer of copper between the contact traces.
Casio fx-180P programmable scientific calculator.
See the obvious mechanical things as well, and also the leakage through the transistor after cleaning the PCB thoroughly, could be damp and dust are forming a resistor.
Cleaned the gap between tracks, it was forming a resistor, problem solved.
The repeated working of the switch had formed a thin layer of copper between the contact traces.
Casio fx-180P programmable scientific calculator.
See the obvious mechanical things as well, and also the leakage through the transistor after cleaning the PCB thoroughly, could be damp and dust are forming a resistor.