Hi all, 

With the help of @Bill I was able to dissasemble my 'dead' inherited Beocenter 9000. This Beocenter was defective; it would start (relay clicks) and 90% of the time would go through some sort of 'boot loop'. Just restarting all the time. Once every X cycle it would kinda boot properly (cd carriage coming on, motor working, etc) but after 2 minuted would again go to the off state. Which would trigger the reboot. 

So. I removed the power supply. On the power supply there were 6 capacitors that were way out of spec, one was dead in the water. Also the soldering of the through hole components was cracked and brittle. These are common issues. The smd caps were also bad as they so often are. So I reworked the board and replaced the defective components. 

Of course I tested every semiconductor on the board, they all checked out fine. Testing the IC's out of circuit is almost impossible but I found no shorts to ground. I did not check the main microprocessor. After this I put the board back in the machine and reconnected. 

Now when the machine gets power nothing happens beside a very slow blinking red LED on the carriage. There is absolutely no life in the machine whatsover, it is completely unresponsive. I have triple checked my work before re-inserting the pcb, I have done this kind of work many many many times, Aside from the slow blinking LED it is totally dead; no relay clicks just nothing. 

The question is what the hell is going on here? 

Kind regards,

Bert