PC wont startup Mind of its own!

[Shanks]

I have a dell dimension 9100 and lately, i have no idea whats causing it, but when i press the power button (Only after a shutdown) to turn it on the fan and the light comes on but the power button turns brown instead of green.The monitor is completely blank no display or startup or anything. Eventually when my computer feels like going on again it will amazingly enough all by itself change that light on the power button from brown to green and go the user login page as if nothing ever happened. Sometimes this process takes 2mins....Sometimes 2hours and sometimes it wont come on no matter how long i wait. This is the first time it started running in the past 3days and i plan to never shutdown until this problem is fixed...*i can restart*

I know its not the power supply because thats at first what i thought it was so i bought a brand new one and still nothing.same results....

Computer Specs....
Windows XP Media Center Edition v2002 Service pack 2
Pentium D 2.8 GHz

PLEASE HELP ME T_~

[GX1_Man]

I would start by posting a question on the appropriate Dell forum. This may be a known issue.  

http://www.dellcommunity.com/supportforums/board?board.id=dim_other

If it is still under warranty I would contact Dell directly.

[Shanks]

yeah its not and they charge about 50$ just to tell you what the problem is if they know what it is. If they dont know whats wrong they DONT refund your money and start blabbing about saving on a new computer blablabla

[GX1_Man]

The support forum is free.

[Computer Hope Admin]

I've never encountered this issue so I'd assume that the forum may be the best bet as well. The only thing I could think of over the night (read your post before going to sleep last night), is possibly a sticky button and/or button malfunction that is not sending the signal to the motherboard. Could also be a defective motherboard.

Another thing that could be tried is to disconnect everything but the power cord and see if the computer comes on immediately after pressing the power button. If so maybe it's a really strange hardware conflict/issue.

[Shanks]

Well thanks for your help everyone i guess ill dry the dell forums they seem pretty nice hehe ^_^. And yeah i tried unplugging everything even unplugging the disk drives to make it go on but nothing still same thing.

[Computer Hope Admin]

Good luck. Sorry couldn't help you further, strange issue indeed. Likely a hardware issue.