I recently tried to replace my 6800GT OC (AGP) with a new 7800GS OC (AGP). I uninstalled the drivers for the first card and then shut the system down to install the new one. After I put the 7800 in, I tried to boot my computer. The operating system would not load and the monitor falls into a "power saving" mode as if the computer wasn't even running. I checked the connection in the back which turned out to be fine. I even took the liberty of going into the BIOS and checking for any descrepancies. Nothing. I took the 7800 out and reinstalled the 6800 - computer booted right up. I went into the device manager and deactivated the card with no installed drivers. I shut the system down again and threw in the 7800 (not literally) and got the same exact problem. It seems that I have had terrible luck with video cards for years and I am stumped once again. I would appreciate ANY help with this. Thanks in advance!

System SPECS:

AMD Athlon XP 3200+ (2.21 Ghz)
2048 GB RAM - 2 DDR DIMM PC3200 sticks (XMS)
K7M-NF18G Micro ATX motherboard - socket A
BFG Tech 6800GT OC (AGP)

Exchange the 'NEW' card.

Are you sure you plugged in everything, including the 4-pin Molex cable required to power the card? Also, is ur PSU adequate enough for the card? If it's 450W+, then I think you should exchange the new card.

The new card (7800) is securely connected to a 520W PSU. The fan runs smoothly so I know the card is powered. I am going to try reloading the CMOS to see if that does anything which I doubt will. Thanks for the fast help.

What brand is the power supply? If it is a no-name brand PSU than it is likley the problem.

The PSU is an ASPIRE (although I'm not sure that the company still exists). I used it to power my two previous cards and have had no problems. As for the 7800, I called BFG Tech and arranged an exchange. Thanks to all that helped out.

ive had the same problem with my radeon x700 still not fixed, ive been told my agp slot is bad yet i can run agp 1x-8x cards in this slot (just have to change the bios settings for the proper card) ive rma'd the x700 and it still doesnt work but all my old cards do its quite annoying