New build killing graphics cards?

I've just finished building a new PC and I'm having real problems. To give you some background, I'm hardly new to building my own PCs having built perhaps seven over the years. This build however is giving me problems and I've run out of ideas. The current system is this:

Gigabyte P35C-DS3R
Core 2 Duo E8400
2x1GB Corsair TwinX DDR2
Antec P182
Corsair 520W HX PSU (this is a modular unit with 20+4, 4 and 8 pin power leads and a modular system for the rest)
Gigabyte 8800GT (the one with the Zalman cooler)

Here's a general shot without the GPU installed:
http://i65.photobucket.com/albums/h225/Bouchehog/P1000753.jpg


And a closer shot with the Gigabyte 8800GT in:
http://i65.photobucket.com/albums/h225/Bouchehog/P1000758.jpg
(Note that the only connections are the case headers, 4- and 24-pin power supplies and the 6-pin power supply to the card)


Initially I had an 8800GT 512mb alphadog rather than the above card. I connected the CPU/heatsink/motherboard/RAM outside the case (on a static-free surface) to the PSU, 8800GT and monitor to see if it would POST. It seemed to power up properly and the CPU and GPU fans spun up; there was no warning bleeps but there did not appear to be any output on the monitor. Obviously there were none of the system headers attached at this point and I turned it on by touching the relevant connections with a screwdriver.

The only strange element initially was that the system powers up, the 3D card fan came on immediately, then the CPU fan a couple of seconds later, then after perhaps four second the whole system shut off. It then restarts and does not shut off (until I turn off the power). I've no idea why it would do this but I wonder if it's connected with the main problem.

I double checked that the 4-pin and 24-pin power supplies were properly in, that the 3d card and RAM was seated properly and that the card's power supply was attached. I tried again with the same result.

Next I checked the power supply on the 3D card - there's an adaptor that comes with the card which takes two 4-pin IDE-type power sockets and connects them via the 6-pin PCIe power connection to the card. I tried using the PSU's PCIe power connector (one lead) instead of the bundled 2x4-pin into one adaptor. No joy. Just to check that the system speaker was working I tried booting without any additional power to the GPU. The warning sound went off as expected.

At this point I borrowed a friend's system to start testing individual parts. His setup has a dual AGP/PCIe motherboard. I hooked up his system with its AGP card to my PSU. It POSTed and booted into XP. I tried one module of my RAM, then the other then both together: again, no problems. I then tried the 8800GT alphadog. The system seemed to boot but didn't display anything. No strange 4s reboot thing on this system though. I tired using both of the card's outputs and using the Dell monitor's DVI input and it's D-Sub (the blue VGA one) input via the DVI-to-D-Sub adaptor. No joy - still no signal to the monitor. I then re-hooked his PSU and when through everything again with the same results.

So, from this I assume that my PSU and RAM is fine, I haven't checked my CPU but the 8800GT seems the most likely problem with it not giving me any love on two different boards. I arranged an RMA on the card and ordered the new one (the Gigabyte 8800GT). In the interim I stuck the PSU and motherboard into my case.

When the new card came today I installed it and booted up. Again, exactly the same results - the 3D card's fan spins up immediately, then after a second the CPU fan, then after 4s both fans stop and nothing happens for a second, then the system starts again with the 3D card's fan starting up, then the CPU fan and the system stays on. Again, no output on the monitor from either of the card's outputs. I tried altering the card's power inputs as before (this card also comes with the same type of adaptor) and then tried it in my friend's PC. Same results as before...

So we finally come down to the questions:

1. What the hell could be causing this 4s reboot thing?
2. How likely is it that I've just been given two bum cards?
3. Is it possible that my PCIe slot (or something else) is killing the cards thus explaining why they don't work in two machines?

Lastly, I should point out that I'm loath to buy another GPU to test until I've got the bottom of this because if it's me being stupid I then have three 8800GTs which I can't return as they might be working... If it helps I still have my friend's PC and both PCIe cards. Any ideas???

 

Has any PCIe video card ever worked on this mobo? I think the mobo is bad. The chance you got 2 bad video cards back to back is pretty slim, unless it's a bad batch, which does happen. You may be able to buy a low end used PCIe video card on EBay or something, maybe a bottom feeder like a Radeon X300 for maybe $30 just to see if it works. Try it on your friend's PC first... if it works, then put it in your board. If it doesn't work, put it back in the friends PC... that should be a good test...

 

Fixed the problem! For anyone suffering the same problems it was simply that the Gigabyte P35C-DS3R (revision 2.0) doesn't support the E8400 CPU unless you happen to have a version that has shipped with BIOS version F10 (very unlikely). In order to fix the problem, grab the latest version of the BIOS from here, expand the files and stick them on a floppy. You'll need to borrow a supported CPU (in my case a E6420) from someone, install that CPU (with heatsink) the 3D card, power supplies and a floppy drive. Then boot into the BIOS and use the F8 function to update the BIOS from your floppy. Once BIOS version F10 (or later in due course) is installed you will have support for the E8400, so switch the CPUs back over, installing the E8400 and boot up. If you've done everything right then you should be able to POST and go on to install whatever you need to. If you still can't POST then you've done something else wrong or one of your components is probably messed up.

For good measure, here's a shot of my happy little system running vista:
http://i65.photobucket.com/albums/h225/Bouchehog/HappyComputer.jpg

 

:celebrate :highfive :hyper :dancer

Nice work figuring out it was the BIOS and all! And it's a good thing you had access to another CPU that the mobo supported.... anyway, I'm happy to see all is well...