Question Red vertical line on a led Acer pc monitor

[fastshot]

I've got this old lcd Acer x193w monitor in a home PC building. It's connected to my PC by a VGA cable and by an IEC cable to my UPS to be supplied.
Today an 1 pixel wide red vertical line appeared on the right side of this monitor in correspondence of its on/off button as soon as I switched it on in; actually I've been pressing this button quite often along the years of usage, if it could be important. I've already tried a monitor factory reset by its buttons but I've not solved.

This line doesn't appears in screenshot images but appears in BIOS environment and in both one of my OSs and it appears even if its VGA cable is disconnected from my PC so I think this issue doesn't deal with my PC components; anyway this is my cfg:
- amd ryzen 2200g with Vega 8;
- msi b450-a pro (bios V10.7; 2019-03-07);
- 2x4gb hyperx predator @3200 cl16 (working @2400 by default)
- wd black 1tb hdd;
- corsair cx450 PSU;
- no graphic card.

Honestly I don't know if this is a monitor electronic issue for sure or I've to consider other ways/things before trying to fix it, anyway I'd like to listen to your opinions.

What do you think the problem is and how to fix it (if possible)?

 

[LinuxDevice]

VGA cables do not support plug-n-play. Some people say they do, but in reality VGA-only monitors only support an earlier protocol (we tend to just call it EDID, but really now it is EDID2; they're supposed to be backwards compatible, but most manufacturers of video cards don't support older EDID). Can you try with either a digital DVI or HDMI or DisplayPort? With older VGA cables it really isn't possible to be certain without testing it on other computers. If this vertical line is still present with a digital type of cable, then it is likely a problem of the monitor (but if you can try the monitor on another computer if and only if a digital type of cable does not solve this).

 

[fastshot]

It's a VGA-only monitor, no DVI or HDMI or DisplayPort and it's the only PC I've got so I can't test this Acer in another PC.
I guess it'd be useless to just get a brand new VGA cable or get a VGA<->HDMI converter and try, wouldn't it be?

Can you explain me the plug-n-play thing again? Honestly I couldn't follow you, in the sense I can't understand how it deals with my issue.