[cohenx]

Thank you a lot for your comments.

I drove to a local computer laboratory and we tested each component. After changing all components only the CPU was left from my old system and there was still no monitor signal. I couldn't believe my eyes but it really was a Intel CPU error.

I replaced the Intel CPU in my old components and everything works fine now. There is no mechanical damage. I dont know exactly if there was an overheating, but I never changed voltages or/and MhZ in BIOS except Memory Voltage and FSB Speed (downgrade).

with best regards,
Martin Huber