I recently replaced my power supply on a dell 9100 Deminsion. I purchased the 600w one and installed it a day ago. Upon installation, everyting seemed to boot up like normal... fans running hard drive spinning, and what not. (I am not technical at all and for that I am sorry). I had no signal to my monitor, so I replaced the video card yesterday, and I still have no Signal to monitor. The computer runs the same as it did before, fans kicking on and hard drives turning... but still no vid signal. I've tried a number of "heard it from this guy" things to do like powering down and unplugging the machine. Hold the power up button for 30 secs and then plug in and power up again. Nothing seems to work. My Vid card is an Asus ENGTS450, if that helps at all... Any suggestions? Could RAM be an issue? Thanks for anything and everything... really at the end of my rope with this tower. USBs wont work either (mouse and keyboard dont respond) but that is another problem for another day I think.