My Dell E2216H stopped working.

I use it as a second monitor for my HP OMEN laptop. It does have somewhat faulty VGA to HDMI cable, which only worked in very specific (down to micron) position, but it worked for the last year at least, until yesterday. Nothing mechanical happened to it, it just refused to take the cable and work normally again.

Today, I figured that:

1. The monitor exits power save mode and works OK if I set smaller resolution (less than 1920x1080) through NVIDIA Control panel or Windows display settings.

2. It breaks down again if I put stuff on that monitor, like a browser with open pdf file in it. The smaller the resolution, the lesser are the chances that it will start blinking or going black completely. Windows decided that the monitor, for some reason, has recommended resolution 1024x768, and it can scarcely handle even that. It worked at full 1920x1080 it's whole life with no issues.

It isn't a problem with power, since even at lowest brightness it does all those things, and just in general it has it's own power cable. The laptop is high performance setting, with a battery out, not that putting it back made a difference.

At this point I'm just curious what exactly is going with it, how putting a pdf file on a monitor can shut it off, why it goes into Power save mode instead of working at it's standard resolution, and why it suddenly decided that it's original resolution is 1024x768.

My laptop specifics are:

GTX 965M

Intel HD Graphics 530

Intel core i7-6700HQ