My Gateway 500X won't display anything on the monitor; it's been dying for a few weeks and finally got to the point where it starts with fans running but nothing displayed on the monitor. Sometimes I have to push the power button several times before it starts booting (fans start running). Prior to this I had spontaneous reboot/shutdown problems while running Windows XP.
I've tried reseating all power cords/harddrive connections/video card/CD ROM/FDD/memory sticks, which hasn't helped.
Could be either one. I would get a good used branded ps around 350-400w for testing, such as antec, fortron fsp (sparkle), corsair, etc if new is out of your budget. If it still won't post, might as well start over and sell off your gateway parts. Your windows operating system won't transfer over unless you've already upgraded it. It may only work with gateway boards.
Update: I found I had a bad video card; when I took it out and plugged into the onboard video adapter, I got the monito to display (with very low resolution). I took my PSU to a local computer repair store and they tested it free; found out is was bad. Got a used one (Enlight Corp. Mod #HPC-300-101 - anyone heard of it?) for $10.00. Computer boots up and hasn't crashed for 24 hrs.
Side Note: In all the messing around, I fried a hard drive by touching the 12V Molex prong to the 5.5V side of the drive (working in the half-dark). Also blew a wireless card.
The hard drive in it is a Seagate 160 GB. I've run Sea Tools for DOS long test on it multiple times and found multiple bad sectors, which it repairs each time I run it. Anyone had similar experience with Sea Tools?
Anyway, thanks for the advice and it looks like the computer will live another year or 2.