I bought these 2 cards today, they are both nVidea Geforce 8400 GS. 512 DDR2.
I plugged one into my ASUS P5LP-LE Board which originally had the 8300 GS card, not much of an upgrade but that one only had 128MB RAM and this one has 512. Anyway I unplugged the 8300 PCI Express and plugged in the 8400 PCI, plugged in the cable, booted up and no video. Hmmm I said to myself? It has to be something simple, maybe I have to unplug the RAM or something. So I unplugged both ram and video plugged both back in, booted up and still no video. Then I plugged in both cards, plugged the cable into the original PCIEx card and it booted up just fine. So then I figured I'd try to install the software for the new card and give that a shot. I then restarted the machine switched the cable to the new card and still no video. Feeling defeated thinking maybe it's my board or Vista or who knows what. I tried the other 8400 PCI on my XP Pro machine which is an Intel® Desktop Board D845EPI which originally just had an ordinary integrated VGA. So I plugged in the cable to the new card on that machine and guess what, no video. I can hear windows boot up but still get a blank screen. Ugh!
Can someone please tell me what I'm doing wrong? This is getting frustrating.
Go into your motherboard's BIOS and disable onboard graphics. See if it works after that. If it doesn't, you can try resetting your CMOS: http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00...
Scroll down that page and you'll find a section that'll help you on resetting the CMOS. Report back with the results.