Nakamichi PA-1 problem

[tarkusnj]

Hello to everybody...I am new on here and have been researching the net to gather any info on troubleshooting my Nakamichi PA-1 5 channel amplifier. It began humming and was not working. Now when I turn it on with nothing connected, I keep hearing a relay click on and off at around 5 second intervals. I believe this is the safety circuitry kicking in. Anyway, When I opened up the amp there are 2 plugs going to connectors for the RCA inputs on the rear. One plug has 3 channels on it while the other has 2. When I disconnect the plug with only the 2 channels, the relay stops clicking. This is all I have discovered and I don't know what else to do. I see nothing that looks fried or blown. I have searched high and low for a service manual for this amp hoping maybe that would help me out. I got an estimate to repair the amp of $350 which I don't want to spend. Can anyone give me an idea how to troubleshoot the main board? That is all the amp has including two big transformers and with 2 boards containing a couple of big capacitors.
thanks to anyone who can steer me in the right direction. The amp is in pieces right now and before I go through the trouble of re-assembling it, I want to give it my best shot.

[tebbi]

Hello,
you can try with a multimeter to measure if its dc on the signal path.Or you try to get a schematic.Then you have voltage assignments you can compare with the amp.But Hum, sounds like a deaf capacitor in the main power unit.
greeting stephan

[tiefbassuebertr]

for description recapping project go to post #352 about
Best electrolytic capacitors