I have an annoying problem when i reboot one of my computers. While the computer is on it is fine. If i reboot or turn it off for a short period of time it will not POST. Stays on a blanbk screen. If i leave it off long enough it will come back on... sometimes. I thought it was a mobo/CPU problem so i replaced them. Even tried a diff PS and it does the same thing. About the only thing i have used from the old system is the hard drive. Has anyone else had this happen? Could the HD be keeping it from POSTing and booting?

"Could the HD be keeping it from POSTing and booting?" Easy to test if the failure is solid. Power off and disconnect the Drive's signal cable. When you power up you should get a display, of course windows will not come up. If you don't get the initial beep, the motherboad/CPU is not operating. It 'could' be something that is connected to the motherboard, like a drive or card. You seem to have eliminated the obvious sources (PSU and MB).

Quazi booting, normally caused by two things. One is static damage and the other is power supply caps holding enough power to hold states. I read it wrong and answer it wrong too. So get off my case you goober.

Well after a lot of switching around... seems to have been the memory stick. I removed it got the regular beeps which made me think it wasn't working with it plugged in. so i switched out a stick from one of other comps and VIOLA! thanks for the input...

Good work Bowtie! Thanks for letting us know the solution.