my config - amd thunderbird 1.1 gb
512 mb sdram (2 256's)
1 - 30gb - 7200rpm hd
48x cd-rom
12x burner/8x dvd combo
1 - floppy
agp 4x geforce2 video card
soundblaster live
1 case fan
250w power supply

i recently upgraded my cpu from an 800mhz duron to the 1100 t-bird with no problems. about a week later, after powering down i needed to power on again and nothing happened. after opening the case i noticed the cpu fan would flinch when i tried to power on. i let it sit overnight and powered up fine the next day.

now another week later and adding the case fan to draw the hot air out this is a consistant problem. after i power down i must let the pc sit about 1 hr, reset the power supply and it usually will come up fine.

i have not failed in any way while running. this only occurs after powering down and immediately (within a minute or two) powering back up. i don't have any more room to add another case fan, the back of the case doesn't feel too warm but the power supply does. am i overtaxing this 250 watt ps?

Yes you are taxing the 250 watt.
The Tbird is power hungry .
Adding the additional fan causing the boot problem to become consistent is a good clue
300 watt is the normal minimum for a Tbird system

Also where is the exhaust fan connected ? To the mother Board or To a power drive connector ?
Having it connected to the M/B and leaching power off the board can cause this also

One rule of thumb says take 200 Watts and add 50 Watts for every 2 devices - you have 4 devices so, using this rule, you would need 300 Watts

While one can never say never or always sounds like you've hit on the first place to start

Also - one thing I keep doing is adding/deleting cards - sooner or later end up with unused opening on an expansion slot. Found out that this is like opening a window in a car when AC running - makes it over heat in that area by disrupting air flow - so now I make sure to close up any unused expansion openings - just a thought

Good Luck http://www.PCGuide.com/ubb/smile.gif

actually the exhaust fan is connected to a power drive connector. i also failed to mention i am also drawing power with my canon scanner that uses the usb connection for it's power source so i'm probably well over the line for that 250 watt psu.

i think i'll purchase a 350 or 400 for future upgrade/expansion consideration.

many thanks to you both for your help and responding to my post!!