Possible PCI-e fault

ballzac

Member
I have a problem with my pc that I think I've managed to narrow down to a motherboard fault, but would like opinions from more knowledgeable people. Sorry for the length of this post. I want to be thorough in explaining the fault and the lengths I've gone to to diagnose it.

I've had this PC for about 3.5 years with no problems. The last upgrade I did was the graphics card, about 18 months ago.

Specs:

Graphics card: MSI GTX970 G1 gaming
Motherboard: Gigabyte Z87 GD-65 gaming
CPU: Intel Core i5-4670k
RAM: 2x8GB G.Skill ripjaws low profile
Cooler: Noctua NH-D14
PSU: Corsair RM750

Recently, I turned on my PC, and although it started up, I got no signal on my monitors. Two of these are plugged into the graphics card, and one in the on-board VGA. None of them showed any signal. However, I hear the windows notification when it detects usb devices, indicating that it is indeed booting up, it's just not providing signal to the monitors.

After some troubleshooting, I discovered that it boots up fine if I take out the graphics card and plug two monitors into the motherboard. I thought it must be a problem with the graphics card, but I tried swapping the card with my girlfriend's (a GTX1050); her pc booted up fine with my graphics card in it, and mine didn't with hers in it.

Her card has no external power connectors, so I thought it was unlikely that my PSU was the problem, but I thought maybe if it wasn't supplying enough power through the PCI-e slots, that this might cause the problem, so to make sure, I swapped our power supplies. My PC (i.e., the one with my motherboard in it), still showed no signal on the monitors. From this, I know that my graphics card and PSU both work in her computer, so I put them back in mine, and took everything else out of my PC except for the cpu, just to see if it will post. Still no signal.

I tried putting my graphics card in a different PCI-e slot, to see if the slot itself was damaged, but still no luck. I can't test the third slot easily because there is no slot in the back of my case to fit it in the bottom PCI-e slot. I have a usb card in a 1x slot, which is working fine.

What I think is up: there is a fault with the motherboard that is causing multiple PCI-e slots to operate incorrectly.

I have looked at replacing the motherboard (it is outside warranty), but the options are less than ideal at the moment. The three places I usually parts from don't stock a lot of boards with the LGA1150 socket. In fact, I can only choose between two almost identical boards. It means I will end up with very little space for expansion, and they have fewer usb slots than I would like. I also won't be able to overclock.

If I knew that the motherboard was definitely faulty, I would bite the bullet and buy a new one, but I want to avoid spending the ~$100 when I'm not 100% sure.

So my questions are:

Is anyone familiar with this type of fault? Is it normal for a PCI-e fault to affect multiple slots? Is there any chance that a CPU fault could cause this? It's the only thing I haven't isolated from the system when testing, and I don't want to buy a new motherboard if there's a chance the cpu could cause this. If it's the motherboard, is it possible there would be a fix? I've tried both BIOS on the board, and I've tried resetting the bios, and also tried flashing the bios to the most recent version. Can anyone think of any other possible causes? Maybe I'm missing something.

Thanks in advance for any help.
 

johnb35

Administrator
Staff member
Remove the motherboard from the pc so you can test the other slots since your case doesn't have the space available. Put it on a piece of cardboard and put it together.
 

ballzac

Member
Thanks. But what will this tell me? Even if it works in the third slot, it's not like I can put it back in my case and continue using it. It's obviously a fair amount of work to do that, which I'll do if it helps me get it working, but not sure how it's actually going to help. Thanks for your help.
 

johnb35

Administrator
Staff member
Well, if it doesn't work in the third slot then you know something is up with the pcie. Have you tried resetting cmos first? If you try those 2 things and it doesn't work then you can bet its a motherboard issue. Building it outside of the case would also verify that the motherboard isn't grounding out against the case somewhere and causing the issue.
 

ballzac

Member
Well, if it doesn't work in the third slot then you know something is up with the pcie.

I've tried in two of the three slots, so I think that's statistically good enough for me. If I take it out, I'll have to put it back in anyway so that I have a working PC while I'm waiting for the motherboard to be delivered. Also, all the cables from the PSU are carefully routed throughout the case, so I'd have to either undo all of that or get the one out of my girlfriend's PC again. It's just a huge amount of hassle and risk of further damaging something while working on it.


Have you tried resetting cmos first?

Yep. Tried that.

Building it outside of the case would also verify that the motherboard isn't grounding out against the case somewhere and causing the issue.

Good point. I hadn't thought of that. However, as I hadn't been anywhere near the inside of the case recently, and there's nothing touching the motherboard on the front side of it, I think this is unlikely. I think my best bet at this stage is just to assume it's a fault and buy the replacement.

Thanks again for your help!
 

ballzac

Member
A quick update: I have managed to get it to start with the graphics card installed. It turns out that there are problems when IGD multi-monitor is turned on. I have three monitors, and one is plugged into the on-board graphics, so I had IGD multi-monitor on. The thing is, because I was moving graphics cards back and forth between PCs, I stopped bothering to plug the monitors back in (I could look at the third one to see if the PC was starting up properly. However, when I cleared the cmos it, of course, set IGD MM back to "off", which meant that me not seeing anything on the on-board was no longer a symptom of the problem, but instead was just because the on-board was disabled while the card was installed. Dumb that I didn't try it again with the other monitors plugged back in until now, but it never occurred to me that there might be a reason this would matter. Anyway, fingers crossed with this. Hopefully there are no further major problems, and I might even be able to find a solution to the IGD MM issue. If not, then I can live with using only two monitors until my next major upgrade.

EDIT: reinstalled motherboard chipset driver, intel graphics driver, and nvidia driver, restarted, re-enabled IGD MM... all working as it should now. Hopefully it stays that way.
 
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