I have computer that occasionally fails to start up. It has the following symptoms:
You can push the power up button and nothing happens.
You can push the power up button and it looks it starting to power up then it shutdowns after few seconds. I don't even see the POST screen.
After it does power up it won't shut down in middle of boot, but may power off suddenly after few hours of work and then symptoms one and two are come again.
What could be the problem?