PG32UCDM Multi-monitor Bugs

[klaxian]

I have two monitors connected to my PC: Asus PG32UCDM (HDMI) and MSI MPG271QRX (DP). However, only ONE is ever enabled at any given time because they are in different areas of the room and used for different purposes. The monitor that is not in use is disabled using the Nvidia control panel to prevent burn-in, lower power usage, and because it is not visible.

This setup exposes a few PG32UCDM bugs that may not be apparent on single-screen setups:

• When the PC is on and awake but the PG32UCDM is disabled (orange LED, standby mode), it keeps displaying "HDMI No Signal" at seemingly random intervals the entire time. This doesn't happen when the PC is asleep or off. I would expect this message to appear once or twice and then the screen should remain black in standby mode. The repeated "No Signal" message itself could cause burn-in and it seems to increase power usage.
• About once per day, the PG32UCDM seems to reset itself when it's in standby (orange LED) and I'm using the other monitor. This might happen after an automated pixel cleaning, but I'm not sure. When this happens, the monitor and the PC behave as if the screen was disconnected from the PC and then reconnected (or powered off/on). It will cause my other monitor to go momentarily black while the PC detects the new configuration. Sometimes the sound output device will even be changed to the PG32UCDM. This is particularly problematic in the middle of a gaming session. I suspect the PG32UCDM  is resetting itself somehow after an automated pixel cleaning. I would expect the PG32UCDM not to affect my PC monitor configuration at all while it's in standby.

The issues I described DO NOT occur when my other monitor is disabled and the PG32UCDM is in use; the MSI works as expected, but the Asus has these bugs. I am running firmware MCM108, but the behavior has been the same with all firmwares and many different nvidia driver versions during the last year. Turning off the PG32UCDM entirely when I'm using my other monitor prevents these problems, but then I have to remember every time and I can't use standby mode as intended. Plus, it's difficult to turn the screen off when it's in standby because it doesn't always respond to button presses and the OSD is not visible/accessible, but I suppose that's a separate bug.

Does anyone else have trouble with a multi-monitor setup like this? How can I escalate these issues to Asus so they can be resolved in a future firmware update?

[Aureliannn_ROG]

Hi @klaxian ,

Thank you for your inquiry. 

To better understand the display-related issues you are experiencing, please provide us with the following information:

Regarding the repeated display of "HDMI No Signal" issue:

1. Single display test: Does this problem still occur if you only connect one display?
2. NVIDIA Control Panel disable: Do you want the PG32UCDM to completely turn off after disabling it through the NVIDIA Control Panel?
3. Message frequency: Does the "HDMI No Signal" message keep appearing until you enable the display again?
4. Indicator light color: What color is the display's indicator light after disabling it through the NVIDIA Control Panel? Does it light up?

Regarding the screen auto-reset issue:

1. Auto power off and on: Do you mean that the display will automatically turn off and then turn back on?
2. Settings restore: Do the settings revert to their default values?
3. Firmware version: Does this issue occur in all firmware versions?
4. Pixel cleaning: If pixel cleaning is performed during standby, the display will flash orange five times to indicate the start of the process, and then flash five times again to indicate the end of the process. You can refer to the FAQ below:
   [LCD Monitor] ROG OLED Gaming Monitor Pixel cleaning process. | Official Support | ROG Global

Thank you.

[klaxian]

Thanks for your response. I'll to my best to answer your questions.

Regarding the repeated display of "HDMI No Signal" issue:

1. No, it does not happen when only one screen is connected, but then I can't disable the PG32UCDM anyway.
2. No, I don't expect the display to completely turn off. It enters standby when it's disabled.
3. Yes, the "HDMI No Signal" keeps appearing at random intervals until I enable the display again.
4. The indicator is solid orange (standby) when the screen is disabled.

I am currently using a long optical HDMI 2.1 cable. I have tested different cables in the past, but I decided to test again with a copper HDMI 1.4 cable to try to eliminate that. The problem DOES NOT happen with the slower copper cable. I have a long HDMI 2.1 copper cable on the way to test that next.

Regarding the screen auto-reset issue:

1. I don't think the display turns off and on; the LED is solid orange the whole time. I think there is a momentary connection issue where the PC thinks the screen has been disconnected and then reconnected, which causes the other screen to go blank momentarily while the PC detects the changed configuration.
2. Yes, I tried a factory reset and the values revert to their defaults. It didn't help.
3. Yes, this has happened in all firmware versions.
4. Sometimes I notice the LED blinking, but it may not be related.

It's possible that both issues are due to a faulty optical HDMI cable, or at least the way the display responds to such a cable. However, it's strange that these issues only happen when the screen is disabled. I have a replacement copper cable on the way. Please keep this thread open until I have a chance to test it.

[klaxian]

I have been testing a new copper HDMI 2.1 cable instead of the Monoprice optical cable I was using. Both are 25ft long. I haven't seen either issue with the new cable. I don't think the optical cable is faulty since it worked fine when the display was active. However, there must still have been some intermittent signals making it to the display when the computer was on and the PG32UCDM was in standby and disabled. If a user only had a single screen or always has all their displays active at all times, they would never notice these issues.

Can your team test this by connecting two displays to a PC, one via an HDMI 2.1 optical cable? Set that one to disabled in Windows. They you should start to see the issues I described. If the PG32UCDM reacts this way to all optical cables when in standby, maybe a firmware update could make it a bit less sensitive in the future.