Hello guys,
It took me some time until I could manage to work on the problem...
Here is a short update on what I made:
I followed all your advises and cleaned the power ribbon cable connectors with contact spray. I even cleaned all the other cables inside the console unit, too. Further I removed all the FX expansion cards, the Apogee word clock card and the 3 ADAT extensions. I opened the CPU unit as well and cleaned all the contacts of any cable that has somehow a connection with the power supply.
The result:
The error is still the same. After around 2 minutes the console shuts down. The CPU unit still works though, I can use the Keyboard, the mouse, but the console wont respond to anything.
I am thinking to just sell it back on ebay and to get my hands on a new one ... any other ideas that could bring me further?
Thanx