Symptoms:  When I push the Power Button, the lights come on for 5 seconds and then go off. That is it. Nothing happens beyond that.

 

I've read up a lot on this problem, and in most cases the advice is to replace the motherboard. And I would have done it by now if it were not for the fact that 1 time out of 20 the computer does start and I can even run diagnostic tests on it (those tests do not show any problems).

 

So what is it? Faulty motherboard, lightpipe, or something else?

 

Thank you for your responces.