PSU not enough for video card

[an51r]

System: e7200(stock), 750i, 2x1gb 1066, hd, optical drive and 9800gtx.

I rarely post here but have been lurking these forums for a while. I am now having what I think may be PSU problems and figured this was the place.

PSU thermaltake purepower 500w, I am aware through some research that this is a low quality unit and I bought it used.

Games loop and glitch after short play times, today the video I was watching developed a weird cross hatch design in it and then I lost video signal which was remedied by rebooting.

Do you think these would be signs of the PSU not performing well? I already have a silverstone 750w on the way but would like your opinion on the issue so I have some idea what is going on with this build. Thanks for your help.

[spursindonesia]

Though the PSU you've got isn't so convincing, i think a defective VGA card could also be the culprit of your problem.