ASUS PG279Q Causing BIOS to Crash and Default

[HouseOfBugs]

So my brother and I are at our wit's end here trying to figure out WHY this is happening.

The TLDR is that when his ASUS PG279Q is connected and he restarts, the BIOS resets to default. It does NOT do this when it is disconnected and we have other monitors hooked up.

If you want to get the full details they are outlined here with support video evidence. It is reproducible 100% of the time too.

Yesterday my little brother called me with a weird issue on the new system that I helped him tweak. We swapped out his older Core i7 3820K and its X79 motherboard with a new Z97 board (Gigabyte Gaming 7 Z97X) and a Core i7 4790K. The system was working perfectly and quick at my place with no issues. He brought it home and once he got all his monitors and other devices connected is when the issues started. Instead of going in depth of each step and different things we tried I am going to just put a bullet point list below.

Here is the issue: When the ASUS PG279Q is connected to the system through the main GTX 970 video card and the system is restarted (particularly on a cold boot) the BIOS hangs and reverts to defaults (peripheral settings, overclocking, preferences, etc).

Note:

This does NOT happen when the monitor is disconnected and others are connected. This is reproducible on-demand 100% of the time.

System Specs:

• NZXT H630 Case
• Gigabyte Z97X Gaming 7 Motherboard
• Intel Core i7 4790K
• Dual Gigabyte Gaming G1 GTX 970
• Corsair H115i Cooler
• 32GB DDR3-2400 Corsair RAM (4x 8GB)
• Samsung EVO 850 512GB SSD
• 3x 1TB in RAID 5 (Intel RST)
• SteelSeries Apex Keyboard
• Logitech G700S Mouse

Monitors:

• Asus PG279Q over DisplayPort
• HP ZR2740W over Dual Link DVI
• HP ZR2740W over DisplayPort

Troubleshooting Steps Attempted (None Worked/Changed the Outcome)

• Removed all RAM but 1 stick
• Tried another stick of known good RAM
• Disconnected ALL drives from motherboard
• Swapped Video card slots
• Ran only 1 video card
• Flashed Motherboard BIOS from F8 to F7 version
• Flashed video card BIOS to stock GTX 970 version
• Removed ALL USB devices including keyboard and mouse
• Removed all USB devices excluding keyboard
• Connected ASUS PG279Q to HDMI (no video at all)
• Factory reset motherboard BIOS
• Checked CMOS Battery voltage (it was OK)
• Switched active motherboard BIOS to backup BIOS
• Checked and re-seated all power cables
• Deleted and re-created Intel RAID arrays
• Reinstalled Windows from new installation ISO and media
• Wiped ALL drives in the computer
• Reinstalled Windows and tested issue with NO drivers installed

As you can see we have tried to cover all our bases but no matter what the BIOS will always crash and reset when the ASUS PG279Q monitor is attached to the system. We can restart over and over as many times as we want with the other monitors connected with no issues but as soon as the ASUS is connected it starts.

I have never seen an issue like this. I have a feeling it is something to do with the UEFI BIOS crashing for some reason due to the ASUS monitor and causing the reset. Given the lack of logging and the Gigabyte DIAG LED not being of much use we are grasping at straws. We did order a new GTX 1070 to see if the same thing happens, if it does we will be replacing the motherboard next.

Here is a video demonstrating the issue: https://www.youtube.com/watch?v=0QvouVdm5YI

Here is the Gigabyte BIOS DIAG LED when it resets to default. You can see it reset when the DIAG light shuts off and comes back up. The BIOS codes are ambiguous at best. Video: https://www.youtube.com/watch?v=AtjBxEjJvbg

If you have any ideas, comments, or suggestions please comment below!

Also posted on my site with the full details: http://www.timothyhoogland.com/2016/08/asus-pg279q-bios/

[lopj245]

I honestly don't know. I've been in the it field for about 6 years and this is the first time I've ever seen anything like this. 

[HouseOfBugs]

I have been in IT for over 10 years and never seen something like this. If someone told me they were having this issue without seeing it I would not believe them.

[0x1e]

The only thing I can think of is that the monitor is faulty.

Is the cable leaking current into the GPU which is then feeding the motherboard? That's really all I can think of.

 

Try another DP cable, (switch the cable with the other one if you don't have a spare)

what if you try a different DP on the GPU?

Tried a DP converter?

Put the PG279Q on DVI, ZR2740W  on DP.

[HouseOfBugs]

4 hours ago, 0x1e said:

The only thing I can think of is that the monitor is faulty.

Is the cable leaking current into the GPU which is then feeding the motherboard? That's really all I can think of.

 

Try another DP cable, (switch the cable with the other one if you don't have a spare)

what if you try a different DP on the GPU?

Tried a DP converter?

Put the PG279Q on DVI, ZR2740W  on DP.

Thanks for the input. I knew we left off some troubleshoot steps. We have tried 4 different DP cables that work with the HP monitors. The ASUS has to be on DP for the full features to work (GSync, 165HZ). One HP is on DP and One HP is on DVI-D.

The current thing is something that I mentioned to him. Because if he disconnects the DP cable and reconnects it before he powers it on for the 2nd time when it would wipe the BIOS it doesn't wipe it. But that means he would have to remove the DP cable EVERY time he boots to avoid the BIOS wipe. He did try powering up the system with the monitor powered off and it didn't make a difference.

 

I am hoping someone has some other ideas. I am leaning to a bad monitor or just a weird bug due to the Monitor+GPU+MB. I have the Acer variant with the same MB and the Gigabyte G1 980TI's and don't have this issue.

[HouseOfBugs]

Just updating everyone. 

 

We tried a different GPU and that did not work. We are replacing the RAM just in case and if that doesn't work we will be replacing the motherboard, thank god for easy Amazon returns.

[HouseOfBugs]

Updating everyone. The issue is that the ASUS monitor is NOT grounded directly. Using a cable that had better grounding and measuring the resistance between the chassis and the monitor chassis we found that any time it was reading 6 ohms or higher it would reset on power on. When we swapped to a different cable that grounded better the issue resolved itself. Never buying an ASUS monitor again. We were able to remove the ground plug on another DP monitor and were able to directly replicate the issue. DO NOT BUY MONITORS WITH POWER BRICKS.