My computer was working fine, than all of a sudden when I went to turn it started to boot than than screen went black and wouldn't turn off. so I unplugged than plugged it back in and now it wont fully turn, when i press the power button nothing happens, the case and cpu fan nor hard drive spin up. but the psu fan come's on and the HD activity light comes on(solid) but not the power light. Also when I press the power button the lights on the keyboard flashes. I removed all pci cards and switch and removed ram and still the same.
The weird thing is, that if I disconnect data cable to the hard drive it spins up, but as soon as i reconnect the data cable(IDE) nothing. Even with the data cable disconnect the fans still don't kick in.
Pull power and signal cable from the HDD. See if the PC will boot until it says "no operating system".
Some computers have diagnostic lights, other BEEP a code. Is your PC beeping at all? If so check the manual for beep codes.
If the PC is not beeping then it is not completing its POST - power on self test. Std debugging is to keep pulling parts off until the system posts, then add them back until you have the failing part. (It's also possible that reseating a part makes it work and when you finish putting everything back the system works.)
When you are down to just the power supply, MB and CPU (everything else disconnected including all non-power wires on the MB if the system still won't post replace power supply first then MB.
Their is no beeping. I tried disconnecting everything, still the same. I've tried clearing the cmos and that didn't work. I tried an old power supply I hand laying around and it still done the same thing, but it was only a 160w psu compared to the current 280w psu. I did notice that the dvd drive light stays solid along with the HD light when I press the power button. I have 2 dvd drive's the light on the master lights up solid but not the slave plus the doors wont open up on both but once i remove the data cable(not the power cable) than press the power button the doors open and close normally.
Ok I removed the power and data cable from both cd rom drive's and hard drive and still nothing. The green light on the mother board is on, and the psu fan kicks in, but not the case or cpu fan. My mouse lights up to.
OK, time to remover more parts. Power off each time, touch the power supply to ground yourself, remove a part like a pci card and try again. When all teh PCI cards are gone remove memory. Keep pulling until it posts.
forgot you tried another PSU already. IF you were down to just MB, CPU and the 160w psu then it's not the PSU. 160w is plenty to have system post. If you had other parts connected then retry the PSU test. A failing PSU can take other parts with it.
I think it's the motherboard and not the cpu as this happened once before, when it happened before, I didn't do nothing except for repeatedly turning it on and unplugging it than all of a sudden it booted. But I did notice for awhile that some times instead of getting the black xp boot screen, I would just get a blank screen than I would haft to do a manual shutdown via power button and boot again.