I have Pentium V 3.0 Ghz Hyper threading system with 915Gav mother board and 256mb of ram. While system was working fine until one day when i started the system and screen was blank with only green light on the monitor blinking. I troubleshooted all the possible things but in vain. Then i tightened the fan of the processor and started the system it worked out system was working fine. But after closing the Cabinet when kept the cabinet in a vertical position same thing happened again. These things kept on repeating. I use to tightened the processor fan and it works. Again when close the cabinet it goes blank. I showed it to my dealer he says that the problem is with motherboard and will need to send to intel people since it is still in warranty period. But i am unable to understand why is it working when in horizontal position with cover open and after closing and restarting the system it goes blank. If the problem is with motherboard it shouldn't start only? Please Help Thanks in advance.