PS3 startup problem

Hello, I’m having a problem with my PS3. When I press the power button, the console turns on for about 15–20 seconds without any video output and then automatically shuts down. I can enter Safe Mode, but when I try to rebuild the database or restore the system, I get an error. I’ve already tried multiple hard drives and replaced the thermal paste, but the problem is still there. i fear the mb is fried.

Can anyone help me? Thanks.