i am going through a really weired problem . everything is working fine , it's just that whenever i turn off my pc it doesn't start immediately afterwards .i mean i need to wait for about 15-20 minutes to successfully start the thing again . it something like i have to wait for it to cool down to normal room temperature . i took note of the twmperature in the bios and it was never more than 38 degrees ,and mobo temp around 24 deg. i have done everything i could . i RESEATED every components i could find on the mobo . i replaced the battery . applied thermal compound . formatted the cmos. cleaned all the components. the pc is 6 years old p4 processor .and i fear there could be some hardware issues . and yes when i power it up immediately after shutdown everything works fine : fan ,hdd and cdd make their usual sound accept for theres no boot , even the motherboard screen doent SHOW up + no beep. i did not do any over-clocking or any other setting in the bios. plz guide me. ps :SORRY 4 my bad english.
My guess is that the power supply is causing this (don't take my word for it). If you have a different power supply, install it and see if it does the same thing... Not sure it would be the power supply but I have had power supplies screw up motherboards.
If there is no bios at start up yet everything turns on then I would have to say its the motherboard. Trying each component individually may HELP but I know not everyone can do this. You TRIED reinstalling windows?