Mac Mini doesn't power up after cpu and Ram upgrade
I've upgraded the cpu of my mac mini and the Ram. The very first boot went fine, the system started (Os X Tiger) and cpu and ram have been detected correctly, but after less than a minute it suddenly power down. I've neve been able to power it up again. No fan, no light, no chime nor video. I can't smell anithing strange, there is no sound at all. I've tried to put back the original cpu and Ram with no luck.
Unfortunately I have no other power supply to test, and I fear the logic board is probably gone, even if I can't really understand how.
I've even tried SMC reset.
Apple store is not an option, this computer is ten years old.
Any other suggestion?