[Ask] Help to disable standby countdown DELL S2421HS.

[johndoe71rus]

I have two DELL S2421HS monitors. The computer is configured to turn off the monitor after 10 minutes of inactivity. Dell monitors have an annoying quirk: they display a countdown message saying "No signal from input <>, entering standby in 4 minutes." On one monitor, I was using DP and somehow disabled this message, and the monitor would turn off quickly. On the other monitor, I was using HDMI and also disabled this message. Now I'm using the first monitor, but the HDMI input is still set to 4 minutes. It's been a while, and I can't remember exactly how I disabled this message. I was hoping it wouldn't matter which input was used on the monitor. Here's the ddcui data from both monitors. They are configured almost identically.

s/n 4Y9VY83 hdmi, no countdown
ddcui_4Y9VY83.txt

s/n 9H21Z83 old DP, now use hdmi with countdown
ddcui_9H21Z83.txt

I think it's the Power mode xd6 setting, but I've already tried all three available options. I've also tried two different HDMI cables.

[rockowitz]

I have no specific information about this. If it's settable anywhere I expect it would be in the OSD. It might be settable using a feature in the manufacturer reserved range, but I wouldn't recommend randomly changing values there unless you want to live dangerously. Reddit might be a better place to post this question. Good luck.