Computer turns on then off and then on again after RAM upgrade

Alright here’s the story. The computer I’m working on just needed an ram upgrade. Running Windows XP with 256 Mb of ram, upgraded it to 2gb of ram. I did the upgrade, closed everything up and went to turn on the computer. Nothing comes up on screen. When I power it up, it turns on for two seconds and then shuts down, only to turn itself back on a second later. I switched back to the old ram and I have the same problem.

I was grounded the whole time I was replacing the ram. The power cable was disconnected. I just put in another power supply to test it and it does the same thing. I’m a tad stumped here, hopefully someone can help me out?