8600GTS installation HELP!

Trying to upgrade my Dell Diminision 8400 form 6800XT to a 8600GTS video card. I have upgraded power supply to a Dell Silent 470, flashed my BIOS for A05 to A09. Problem is PC will not boot with new card installed. PC freezes on dimmed Windows XP boot screen. Even freezes on F8 trying to load up safe mode. This is the second card I've tried, purchased new for newEgg.com. Both cards act exactly the same so I really suspect that it is my machine and not the video card. I can swap the 6800xt back in and everything works like it should.

Diminision 8400, pentium 4 HT, 3.0gHZ, 2g 400mHZ DDR2 RAM, PCIe X16 video slot enebled, 160G Western digital HD, BIOS A09, PS Dell silent 470 (520watts peak) +12v @26amps

 

Have you tried the computer with the new PSU and newly flashed BIOS but with the old graphics card? (Sorry it didn't seem clear if you had from your original post.)

Also, have you connected the 6pin power supply to the 8600GTS?

 

Sorry I wasn't clear. New PS and Bios flash working great with old card (6800XT). With new card 8600GTS installed, the PC freezes on boot at boot screen and screen is very dim. Can't get to point for system to recognize new hardware also cannot start in safe mode. I can pull the new card and put the old one back in place and system boots normally and works great.

 

6 pin power supply is connected to the 8600GTS. Checked spec on Dell Silent 470 and +12v rail has 26 amps avail.

 

OK, this either narrows it down to the 8600GTS, PSU or the motherboard.

Can you try a more powerful PSU at all? Just seems that 470w may not be strong enough.
Or can you try the 8600GTS in another pc?

 

Don't have another PS available nor another PC with a PS larger than 350W. If it was mother board , don't you think that the 6800XT would not function properly? EVGA specs on the 8600GTS call for 400W PS ... the Dell silent 470 is 470 watts continious with a peak of 520 watts. EVGA also specs card power requirements +12v @ 25amps. The Dell 470 PS has +12v @ 26 amps.

 

Hmmm, in that case I'd imagine there's a problem with the card or the motherboard.

I say motherboard, because I used to have a Gigabyte socket 754 board that would not accept an old Radeon 9200 card but would take every other card available. The 9200 would work fine in any other PC.
Try the 8600GTS in the pc with the 350w psu - I don't recommend keeping it in there for a long period of time but it's worth a shot surely?

 

I cannot run in other PC as the PS does not have 6 pin plug for +12v and no PCIe slot. Guess that I will have to accept the fact that it is my MB is just not compatable with a DirectX 10 card. I just don't believe that I could get 2 new cards that have exactly the same problems. I just hope I can talk newegg into a refund on a non-refundable purchase!

 

It will run without the 6 pin power connector, you will just be prompted with an nVidia popup in Windows to connect it, and won't be able to use it to it's full capacity.