XG27UCDMG Firmware MCM104 install failure

[DevBlocky]

I just purchased this monitor and it works great, other than the frustrating firmware experience. Each time I tried installing the MCM104 firmware, it would say "Fail" with the USB method, or "FAIL 0x0000, please close then retry" with the One Key method. I tried all sorts of "tricks" I found online, from disconnecting all cables expect power / DP / Flash Drive, to messing with the USB Setup options in Settings, to using a USB-C display, to disconnecting all USB devices from my PC except the mouse and KVM cable, to disabling HDR, etc. (And yes, I made sure I was following the SOPs multiple times).

Eventually, I tried install MCM103 out of desperation, and it worked immediately. Therefore, I think there's something wrong with the newest firmware that came out only 4 days ago. I would love to update to the newest firmware because it looks like it has some nice fixes/improvements, so any advice would be great!

[Aureliannn_ROG]

Hi @DevBlocky ,

thank you for providing detailed information regarding the issue you encountered while updating the firmware on your XG27UCDMG monitor.

To help us further investigate the situation, could you please confirm the following:

1. Did you follow the firmware update instructions (SOP) included in the firmware package?
2. Were there any other USB devices connected to the monitor during the update process?
3. What type of connection were you using to perform the update (USB-C, HDMI, or DisplayPort)? Also, were you using the original cable that came with the monitor?

Once we receive your response, we’ll continue to assist you accordingly. Thank you!

[DevBlocky]

1. Yes I did follow the SOP, for both USB and OneKey. I quadruple checked
2. I tried unplugging just about everything except the power. It didn't work with only DP or only USB-C (and I need at least one input to use the USB method). I also tried with my normal USB devices plugged in, still no dice.
3. I tried using the USB-A to USB-B with OneKey w/o success. I also have my main PC setup for DP and my laptop setup for USB-C, while using the monitor as a KVM, and I tried the USB method with both inputs. Everything is the original cable except the DP, but I unplugged it when using the USB-C input for updates.

[leo6666]

I had the same problem with the same prompt "FAIL 0x0000, please close then retry". I tried restarting XG27UDMG or PC but couldn't solve it. What should I do?

[DevBlocky · Accepted solution]

Incredible support, from both this forum and the ASUS text support service (sarcasm)

I ended up resolving the situation myself, even if I'm not exactly sure how. The USB method still did not work, but the OneKey method magically worked after a couple tries on a brand new desktop computer. I could not tell you why this worked, since the connections to the monitor were exactly the same except the computer on the other side.

So if you're experiencing this problem: Just buy a new computer I guess