Motherboard problem? Asrock Z370 PRO4 PCIE port issue - Page 1
Forum section: electronics / repair

author: xboxgamer
author_rank: Contributor
timestamp: September 07, 2024, 03:20:29 am
content: PC specs:MB Asrock Z370 Pro4CPU: Intel 8700kGPU: MSI 1070TII suspect I have problem with my motherboard.MB was working perfectly fine since I bought it in 2018 up until a month ago when the problems started. First I would get frequent blue screens with crashed video driver (nvlddmkm.sys).By trial and error I determined that when I change the PCIE slot from x16 to x4 for my GPU, PC becomes much more stable. I can sometimes work whole day without BSOD but still occasionally I get the BSOD like 2 days ago where I was working on project in GNS3 whole night and suddenly PC crashed and I lost all my work. Moreover now booting up my PC is a big lottery, 4/5 times I press power on button I can hear fans spinning but no light on keyboard, no monitor no mouse, i then have to restart it 5 times and then eventually it will boot and work like described before, sometimes whole day, sometimes couple of hours without crash.Steps I try to resolve: took out whole MB out, cleaned from any dust but there was almost none, cleaned PCIe slot inside with brush, re-seated RAM, tried to boot single RAM stick in all banks, still the same, re-flashed BIOS.Took out CPU and cleaned it, not problem with MB pins or CPU discoloration. Checked whole MB for any bulged or leaked capacitors. I checked diode reading of all diodes next to PCIE x16 slot, all pairs had the same reading.I then found EVGA KB article how to check voltages on each cables from PSU, created a jumper and I checked every single cable in PSU going either to GPU or CPU and 24 pin plug. All had voltages within specs (3.3V, 5V, 12V).Also I tried to put GPU back to PCIE x16 slot and PC booted up normally but when I opened GPU-Z I saw that PCIE speed is reported sometimes as x4, sometimes even x1. Occasionally it will show x16 but after some time it will still crash.All this makes me believe that there is a motherboard problem. I haven't tried putting my GPU into another motherboard because I don't have one yet. I already ordered another MB from Aliexpress (same model) but decided to ask if anybody knows what could be the issue.Could this be something easily fixable? Or chipset problem and not a chance to fix without reballing? One thing that comes to my mind is maybe VRM unstable voltage but I am not that advanced so I might need help to find the cause here.Please throw some ideas what to check and I will follow your guidance. Thanks

author: indeterminate
author_rank: Regular Contributor
timestamp: September 07, 2024, 10:51:42 am
content: You can chk out the voltages on the bus but i suspect that the problem is not there.https://en.wikipedia.org/wiki/PCI_ExpressIt sounds more like an intermittent fault " solder joint , cracked resister etc " with a clock line or data lane.you could chk if one of the termination resisters in Lane 0 reads differently to lane 1 , 2 etc see the wiki page.how data is sent over the pcie bushttps://ww1.microchip.com/downloads/en/DeviceDoc/PCIE%20Express.pdfthis is very difficult stuff to debug without sum fancy test gear

author: xboxgamer
author_rank: Contributor
timestamp: September 14, 2024, 02:14:09 am
content: Update:My replacement motherboard from Aliexpress just arrived and unless the MB from Ali is also faulty in the same way (I say fairly unlikely) then it's not a MB issue because it acts exactly the same way. Still Card is shown as Pcie x4 in x16 slot and already my PC hanged once during booting up.This leads me to believe it's a GPU issue. I already took my 1070TI apart and I can't spot anything obvious.Except that all VRM's show dead short to ground but I think this should be normal.

author: wraper
author_rank: Unknown
timestamp: September 14, 2024, 02:23:57 am
content: Why don't you run it with no graphics card inserted? 8700k has igpu after all.

author: xboxgamer
author_rank: Contributor
timestamp: September 14, 2024, 02:28:23 am
content: Quote from: wraper on September 14, 2024, 02:23:57 amI actually do right nowBut my intention is to fix the GPU hopefully.

author: wraper
author_rank: Unknown
timestamp: September 14, 2024, 02:35:01 am
content: Quote from: xboxgamer on September 14, 2024, 02:28:23 amYour intention should be to find the cause of the issue, not fix something that's probably not broken.

author: xboxgamer
author_rank: Contributor
timestamp: September 14, 2024, 03:26:31 am
content: Quote from: wraper on September 14, 2024, 02:35:01 amI'm not sure what you mean. I tested GPU on two motherboards, the issue remains. If your point was that it's not GPU then I would agree that I am not sure if GPU is 100% at fault.That's why I was hoping that someone could point my at what could the the cause of GPU showing as x4. I don't really see the point in your comment other than trying to sound smirky unfortunately.

author: indeterminate
author_rank: Regular Contributor
timestamp: September 15, 2024, 10:00:54 pm
content: Have you tried cleaning the card edge connector

author: depeje
author_rank: Contributor
timestamp: September 17, 2024, 02:37:53 pm
content: Did you try swapping out the PSU? Given you tested it with no load, it could be behaving completely different in the system.

author: ivandiazalvarez@gmail.com
author_rank: Newbie
timestamp: September 22, 2024, 07:02:10 pm
content: Hi, reached here due to the same problem, and reading your post arrived at the solution, your problem probably is mechanical, the heatsink of the pch in this pcb doesn´t allow to sit some gpus totally in the slot, that was the reason you got 8x or 4x occasionally and it worked better at 4xI solved the problems plugging my 1080ti on the last pciex1, this will make the problems dissapear, and at 3.0 speeds 1x still works ok. To use the full 16x you can use a slot extender

author: Twoflower
author_rank: Frequent Contributor
timestamp: September 22, 2024, 07:44:49 pm
content: Had a similar issue. In my case the picture froze everything else still worked. The problem happened in Windows and Linux; even swappend GPU from one generation to the next.I noticed that I could still SSH to the box while the picture is frozen. And the dmesg indicated that the "GPU has fallen off the bus". And actually that really brought me to the solution: I supported the GPU on the front side a little and it seems that the problem is gone :-) I don't thing that the error message meant to be so literal as it was in that case.I Assuming you have a tower with the GPU is hanging horizontal in the slot. That your problem gets better if you switch to 4x might indicate the same issue as the disabled lanes are located closer to the front.You could try to put your PC on the side or support the GPU a little to reduce the load on the connector.

author: Bryn
author_rank: Regular Contributor
timestamp: September 23, 2024, 05:40:14 am
content: xboxgamer, try any of these solutions:The top solution would probably be to reset the BIOS settings to their factory defaults (and can be done by removing the CMOS battery from the motherboard for a few minutes, or using a CMOS reset jumper if you have one)If you have other PCIe cards lying about, test them in the same slots as the ones you had (to determine if the issue is to do with the specific card you used). Also test with a spare power supply if you have that as wellYou mentioned earlier that you have a crashed driver, so how about uninstalling it and reinstalling it to the latest version if possibleIf none of these work, try to make sure that the motherboard is not "shorting" with the case (meaning that its performance can be affected by improperly installed standoffs, such as RAM sticks and PCIe cards)Hope any of these work out for you, even though you said you have a new one to do you just now.