Please go to device manager, and look for "Monitors" category. What is your display listed as?
Try to upgrade the monitor drivers, by properties, update.
The cable used has no effect on the back lighting of the display, so not sure what you mean by indirect illumination.
Ar you playing audio through the monitor speakers or something? I am not understanding why it is easier to use HDMI than DVI. Once plugged in, why would you need to unplug it?
Seems like somethings wrong, the behavior you are describing is opposite of what should be happening. Setting it to 0 should give you the borderless image. A setting higher than 0 is for "underscan" meaning it will "shrink" the image to fit the actual native resolution of the monitor (really meant for TV's, but works the same either way).
I'm guessing that either a left over from your Nvidia drivers is causing the issue or a bad AMD driver install. I would run sweepers for both companies to make sure everything is being removed and start from scratch. Could also be Windows getting in the way if it installed some display drivers/software between the time you uninstalled the Nvidia card and installed the AMD card.
ditch the hdmi and use a dvi cable?
Its the last option I have kept.
Its the last option I have kept.
It says Generic PnP monitor under monitors.
I think the monitor is being improperly detected/operated as a "TV" mode, so the video card is using an improper color space for the monitor (gray-scale/illumination).
See if you can get the computer to load a "monitor" driver for the display, instead of a "TV" driver.