Today I bought a brand new PCI Express GeForce 7600 GT for my Dell Dimension 4700 (Windows XP Home, 1.5GB RAM, 3.0Gh Pentium 4) and I am at my WITS end! After I installed it and turned on my computer, nothing showed up on the monitor. I can hear the GPU's fan whirring but no picture. I checked for some of the obvious problems: I double checked my monitor connections and uninstalled my previous drivers but neither seemed to work. I EVEN tried another CARD and that didn't work either. However when I put in my previous card (a PCI GeForce 5500 FX) everything runs fine. Should I just assume that my PCI Express slot is bad and (gasp!) have my motherboard replaced, or are there other things I should look for? Please help!Well that PSU is only 305w. so it may not have enough horsepower to even run that card. What other components are in there?

Here is a basic wattage estimate calculator:

http://journeysystems.com/power_supply_calculator.php

The card could be bad, but if the machine has been working fine until now I would not jump to a motherboard conclusion. Can you test that card in another machine?i would assume that u have a defective card.Actually I replaced the standard 305W PSU with a 400W one. According to the literature in the box, the card requires a PSU with 350W. The card may very well be defective, but since right now I do not have another machine with a PCI Express bus, I cannot test it. Although, as I mentioned in the first post, I tried another PCI Express card (also brand new) in the same slot and got the same results. Besides the possibility that both cards are defective, is there anything else I can TRY?Tell us about the 400 w PSU. Dells are proprietary historically even in regards to PSU's. WHat is the make, model and age of the new one. Besides the pin outs, the 12v rail is the important factor with high end graphics cards. The possibility of two video cards being defective seems a little remote as a possibility but stranger things have happened.I bought the PSU at almost the same time as my graphics card. Since I am not experienced in the least at installing them, I just had the guys at the computer store do it. They did mention the possibility of it being proprietary but they were able to install it.

Now I may not be an expert in power supplies (or hardware in general), but I really don't have too much in my computer. Excluding the new graphics card, all i have is:

(1) DVD ROM drive
(1) HDD
(1) 3.0 Gh Pentium 4 Proc

Sound, Networking and everything else is on the board. The only card I have in there is the graphics card. Like I said, I could hear everything working (hard drive whirring, fans spinning, etc.) but the monitor remains blank. Hopefully, I will get the chance to test the card elsewhere. That hopefully will shed some light on the situation. Until then, I can use all the help I can get.That would be the logical next step. If the card is good we can look at other issues. If it is not, you can continue loving your computer.