d901c Wont Post With Only One Graphics Card Installed

Hello

I am having a rather strange problem with my d901c. I have dual 7950gtx graphics cards, and I suspect one of them is damaged. I am getting bluescreens in Windows7 x64 every time I try to enable SLI.

I cleaned out the machine and tried swapping the graphics cards around, and I got the VGA problem beeps from the bios (one long, two short I believe).

My problem is that I tried each of the cards alone in the primary graphics card slot (slot A according to the service manual, the one closest to the edge of the case), and it would not post with either card. I tried them in slot B just to be sure, and same problem.

I need to id which graphic card is actually bad, so I can bake it, but obviously don't want to bake the wrong one lol. Can anyone identify what I am missing?

I assume that you can run the machine with only one card, even if it came from the factory as an SLI rig.

Thanks for your time.

 

Did you look in the BIOS to see if you can disable the SLI and use only one card?

Some of the laptop SLI configs I have seen actually use something like an adapter integrated into the heatsink/fan assembly in order to allow two cards to be used with just one interface on the motherboard. If that's the case you may have to remove the entire assembly and just stick one card in the motherboard socket.

 

That is not the case with the d900 series, it has 2 full MXM slots and an sli cable to connect the 2 cards. It should post with only one card, not sure why it wont.

 

It probably is because of the vbios, check if they are the same. If not, you have to copy the vbios of the master/father to the secondary /daughter card.

 

Veto that, I have two different vbioses on my 2 8800m GTX and they work fine in SLI. I'd suspect the same as you - that one graphics card might be defective.

 

I still can't think of a good reason why it refuses to work in a non-SLI configuration...

Have you contacted Clevo to see if there is some kind of trick to this, a jumper hidden somewhere, etc...?

 

Thanks for the replies. There is nothing in the bios that I can see regarding the graphics cards at all. My machine has no SLI cable. I have read somewhere that in some instances you dont need one, specifically with 7950s if I remember.

I will try contacting Clevo about this, maybe there is a jumper or a trick to making this work. In the meantime, the machine will boot and perform most normal functions with both graphics cards installed in their original positions, but crashes when starting any graphics intensive program (Combustion, 3ds max, etc.) Its as though anytime it tries to poll the bad graphics card for any reason, it crashes. Gpu-z even crashes the machine.

I suspect it is the secondary graphics card that is bad, due to the bios beeps when I switched them around, but that is just not definitive enough for me to rely on what I suspect.

I will post any information I get about using a single card in an SLI configured machine.

 

sounds like a dead motherboard to me, especially if the system does not work with either card in the single slot.

 

It might be the mb, but that doesn't really make sense since the machine gives me error beeps by just trading the slots, yet boots normally with the cards in their original slots. I am still left trying to find out just which physical card is bad.

 

the chances of both cards going belly up at the same time is very slim. so i would say a soldering point in your motherboard has gone bad, most likely a gpu-location soldering point. probably looking around $300 to repair this, unfortunately.

 

Yea, at least one of the cards is still working fine, thus the normal boot still with the cards in the original slots they shipped in.

 

if you plan on keeping this laptop i would recommend you send it in for repair. both gpu's dying at the same time is extremely rare. i am betting a soldering point in the motherboard has gone bad.

 

Again, obviously at least one of the graphics cards is fine. I am doing this post on my laptop. Yet, when I swap the position the graphics cards are in, it wont post and gives me the vga problem beeps from the bios. It is possible that one of the graphics cards and the motherboard is bad, but not very likely. What is most likely at this point is that the secondary graphics card is bad, because that is the card that is in the primary graphics card slot when the machine refuses to post. I am just not sure.

 

Does anyone know of any diagnostic utilities that can stress one card at a time in an SLI configuration? That should reveal the culprit, if such a diagnostic is possible.