Ok, after much discouragement from my last post, I was able to overcome the obstacles and get the amplifier to power up! I replaced quite a few blown transistors, many blown resistors, and a shorted capacitor. Atleast now parts aren't catching on fire!
But now, when hooked up to an input source, the amplifier won't produce any sound. I traced it down to the protection circuit. It is not activating the relay that connects the RCA inputs to the speaker outputs. From the service manual it says that I should be getting a certain voltage at a particular pin on the IC protector and I am not. There seems to be a fault that is keeping the IC protector from activating the relay. Any ideas on what it could be?
One other question... setting the output alignment, manual says 9-18 mV. On the old good channel it is right within spec, but on the channel I repaired I can't get it up above 1 mV. Any ideas there? Could this be the cause of the above problem?
daveoxide
Unregistered guest
Posted on
Nevermind, figured out what happened. I had replaced two little transistors (two of many), and when I did, I swapped their position on accident. Doh! I swapped them to the way they should be and viola, it works! Actually the amp works quite well, I am pretty impressed. Now that I have a working amp, I have to start construction of my BA subwoofer. Man I love this stuff!