Dear go4expert I am sorry bothering you with my questions.The last time when I used my old motherboard,was the time when I was making format for my laptop. During format I delete all data from HDD,after deleting them a time later during installation ,my laptop shut downed and never turned on due to motherboard issues. I bought a new motherboard from ebay and I installed it.The laptop seems to be working but the screen was black,neither the HP message at the beginnig was displayed.Do you think that's why the laptop did not respond when I installed the new motherboard(due to format)or for other reason? After I installed the new motherboard I communicated with seller and he told me : " My serviceman launched motherboard with procesor P4 2,4/533MHz and DDR1 333 MHz. Motherboard not working with processors bus frequency 800MHz. Your processor probably is 800MHz. Try put lower procesor with frequancy 533MHz and DDR1 333MHz" In my old motherboard I used CPU 3.20 Ghz DDR1 333 MHz.With the new motherboard the laptop was working(DvD,fans,) except the screen,I tested with external monito via RGB,without a hope. After telling me these words , we agreed to refund me the motherboard,but I did not think the format factor until now.Do you think that is the problem or it does not matter? Please I would be grateful if you could help me .I have sent the motherboard to the post but Monday will leave from post,so if you think that's the problem I will go to prevent from leaving... Please help Thank you. :undecided:nonod: