I hava a vaio PC and suddenly it doesn't start. when I push the on button I can hear the beep the power button starts turns on for a second and then turns off but I can hear the fan is running, does anyone know what can be the reason? also the monitor is not displaying anything.

thanks in advance

Laptop or desktop?

Reset your cmos settings.

Try reseating the memory sticks. Run your system with one stick installed. Test it one a time in different slots.

it's a pc. before this happened I changed the dvd-rom drive for a new one and it was working perfect for a week and then I sent my pc to my another apartment via UPS and then it stopped working. the pc was perfectly protected so what I was thinking was that maybe something got disconnected inside? any ideas?

thanks

sorry it is a desktop

Okay, the best way to do is unplug and plug them again. There is something loose connection inside the cpu unit. Check everything.. Be sure they are all snugly and properly seated and connected. Reseat memory sticks and video card.

Just a simple thought. If you are attempting to find loose items within your PC, I hope that you have taken the precaution of using an anti-static wrist strap. I am probably trying to suggest something that you will do automatically but it is always better to be safe now, rather than sorry later