Upgrading a Dell 4500S, Graphics Card Issues

[crivelliman]

I had a quick few issues with upgrading this machine. Here are my specs:
Dell Dimension 4500S
Pentium 4 CPU 1.80 GHz
1.25 GB of RAM

Couple of things:

Just put in 1G of RAM without incident, displacing one of two 256's, and according to Dell I can go for a max of 2Gs. Just checking on that accuracy.

My biggest issue, however, is my graphics card. Trying to use a GeForce 6200 PCI DDR2 256 MB card, and the only problem I'm having is, when it's installed, the computer either a) doesn't turn back on (when the power button is impressed, the yellow light comes on and flashes), or b) if it does boot, the computer will make it through the first prompt, and then shut off. I've had this issue once, sent it back to Newegg, and they sent me a new one. Same effect. I know I'm doing something wrong.

Thanks so much!

[mjc]

Sounds like the power supply doesn't have enough backbone to handle the video card upgrade...do you know the specs for it or can you supply your Service tag number?