GPU not detected in top PCIE slot after CPU upgrade

Daaaveee · 29 Dec 2016 at 14:28

I've just picked up a second hand delidded and lapped i7 6700K to replace my i5 6600K, and the wife will get a nice upgrade to that from the i3 6100. However I seem to have a bit of an issue, not sure if its the CPU or motherboard, or something else thats the issue.

I installed the 6700K, it booted up fine but the GPU was not detected. I reseated the 1070, checked all power cables and reset CMOS but it still didn't detect it. Plugged the monitor in to the IGPU and it gave a signal, so I checked the BIOS and it was set to output display to PCIE 1 first so no issues there. I then tried the GPU in the lower PCIE slot (8x speed instead of 16x on my Gigabyte Z170MX), and it detects the GPU fine and is working OK.

It was fine with my 6600K previously so I'm not sure where the issue is. The IHS had slipped during the shipping and was at around a 45 degree angle, so I slowly and gently rotated it back to its correct orientation. Maybe the Liquid Ultra under the IHS has been pushed off the die and has done something? I don't know much about the delidding and die to IHS TIM application procedure, and have not used Liquid Ultra myself.

The motherboard is the Gigabyte Z170MX-Gaming 5 and is running the latest bios. Any help appreciated!

Daaaveee · 29 Dec 2016 at 15:27

Thanks for your help, just tried disabling the onboard GPU but the GPU is still not detected. The initial display output is set to PCIe slot 1 as well.

GPU is back in the lower slot now and working fine. Not ideal but at least its got me up and running.

Daaaveee · 29 Dec 2016 at 15:49

spolsh said:
Try the 6600k in there again, at least you'll know if it's CPU or board that's the problem.

It was fine with the 6600K this morning at least.

Daaaveee · 29 Dec 2016 at 17:15

vapor matt said:
try turning 1st pcie slot to 8x see if it outputs a signal then. and other devices using the PCIE bus?

Looking through the BIOS there doesn't appear to be an option to do this.

Nothing in else the PCIE slots or M.2 slot.

Thanks for your help

Daaaveee · 29 Dec 2016 at 18:43

Haha thanks Stelly. Tested the GPU in the wife's PC and no issues there. Her 1060 also doesn't work in the top slot either.

I'll try what darket has suggested and report back, it definitely sounds feasible

Daaaveee · 30 Dec 2016 at 16:03

Well I found the problem, I'm a complete idiot, over tightened the CPU cooler and bent the PCB in one corner! I think I was lucky not to damage it further. It seems fine other than the top PCIE slot not working. Hopefully no other issues crop up in the future but I guess it depends what those 4 or so pins are for?

Not sure what I was thinking tightening the cooler so much :confused:

Live and learn I guess!

Here are some photos for your amusement:

Daaaveee · 30 Dec 2016 at 19:03

I tried to bend it back but it's going to need more force than I'd be comfortable applying to get it straight I think.

The cooler is the Cryorig H7, it has threaded bolts and Philips head screws on the underside, I just tightened them up, not really thinking that they were too tight but obviously they were.

TIM is Thermal Grizzly Kryonaut, just applied using the applicator as thin as I could. Looks a little extra around the edges but temps were great. It's OCd to 4.6ghz no problem with 1.35v for the moment, max temps 70c in realbench with low speed fan profiles.

Daaaveee · 31 Dec 2016 at 15:56

I'm pretty sure it wasn't damaged before, I didn't take a really close look at it but I'm sure I would have noticed it as it was quite obvious when I removed it.

I'm going to leave it as is for now as it's all working OK apart from the top PCIE slot, I will really be kicking myself if I broke it even further!

Thanks everyone for the help and input.