PCIe Slot or PSU... Scratching my head.

[rk7596]

I'm not usually stumped by this kind of thing... here's the story.

I get home. I game for a few hours, as usual. I restart the machine to switch to Linux... and I'm greeted by nothing but a black screen.

* The system POSTs,
* gets into GRUB,
* and GRUB starts Windows 10 again because it's set to boot the previously booted entry.
* I hear the startup noise, see HDD activity and all that jazz.

So the PC itself is fine.

* I remove the graphics card, fearing that it's suddenly died.
* I move the monitor cable to the onboard DVI... Intel HD Graphics 4000, hurray.
* I get into the UEFI.
* The UEFI's 'system browser' shows that nothing is inserted in the PCIe slot, but doesn't otherwise indicate that anything is wrong.
* The fans on any GPU I put in the system do spin up.
* I tried an old HD 3870x2 and a known-working GTX 460 from another PC in the house... so it's not the GPU.
 

The motherboard is an ASRock Z77E-ITX. I have one PCIe slot to work with, so no testing other slots. I have only the two required PCIe Power cables from the PSU. I haven't tried the molex adapter yet... but I'm doubtful it's the PSU (the 600W PSU included with the Silverstone SG07). I don't have a GPU that doesn't require power cables to test whether there's an issue with the PSU's cables... but again, I really doubt it's the PSU.

Has anyone here ever had a PCIe slot suddenly die like this? It went from working flawlessly, no symptoms whatsoever to not detecting any inserted card. I've never had a PCIe slot go bad on me, so this would be a first... and the reason I'm posting here.

I'm just floored by how suddenly whatever it was that failed... failed... and I'm confused about whether it's definitely the PCIe slot or not. To go from gaming for a few hours to rebooting to a black screen with no symptoms in-between is just... weird... and I'd be interested in hearing from anyone who's had this happen.

The motherboard is still under warranty, fortunately, but I don't want to RMA the motherboard if it's the power supply and vice versa.

Bleh.
Rob.

Edited September 20, 2015 by rk7596

[ccokeman]

Do you have the IGP turned off in the BIOS? Did you recently flash the BIOS? 

[rk7596]

Prior to the failure, the iGPU was disabled. It's been on the latest 'BIOS' for over a year (1.90).

[SpikeSoprano]

Do you have a multy meter to check for volts at the video card plugs from your psu ?

[rk7596]

Nope. In order to determine whether or not it's the PSU's PCIe power cables, I'm gonna pop in the HD 7750 from a relative's PC, because it doesn't require additional power (once he has time to bring it over here). If that doesn't work, it has to be the slot... and if that's the case, ASRock has already offered to replace it via RMA, at least.

Edited September 20, 2015 by rk7596

[SpikeSoprano]

Sounds like you have it covered, that would be the best way to check it .

[gebraset]

Looking forward to hearing if it is indeed the PCIe slot, which honestly, it sounds like it might be. But, without a way to test the PSU, you won't know for sure until you try out that other video card from your relative.

[rk7596]

Bought a new case and power supply, shipped the motherboard to ASRock for repair ($50 + initial shipping, 3 months out of warranty -_-). 2 weeks later, I receive the replacement motherboard (a different refurbished unit). I rebuild the PC in the SG13. Finished it at midnight on the day the motherboard arrived. Got some light gaming in, put a YouTube playlist on and went to sleep.

Next morning, still working fine. Leave for class.

Black screen when I got home. Not asleep (not set up to 'sleep' / S1-S5).

Power cycle. No POST.

Clear CMOS. Power cycle. No POST.

Remove graphics card, clear CMOS. POST.

Disable iGPU, insert graphics card. No POST.

Remove graphics card, clear CMOS, set usual CMOS settings (4.4 GHz overclock, XMP profile, etc). POST. OS. Running fine (just like last time) ever since. Typing this from my GPU-phobic PC right now, actually. So depressing.

Same thing happening all over again. No graphics card allows the system to POST.

ASRock and I are both mystified. Not the GPU, works in other systems. Not the PSU, replaced that.

I'm pretty sure a graphics card can't damage a motherboard.

Edited October 16, 2015 by rk7596