Backlight issue: dark semicircle appears on right side of screen

So this is a second hand Samsung SyncMaster S23B300 (23") HD DVI monitor but worked fine when I first got it, daily use, no issues till recently so hopefully the previous owner didn't know about it.

The issue is, when I turn the monitor on after it being off, a dark semicircular shadow radiates from the right side. If I press on the plastic frame, things return to normal, and after a bit of fiddling I can get it stable and make the screen appear normal again. However, this is becoming more frequent and more difficult to remedy each time it happens.

It seems like a small issue and I am used to fixing things myself, I can solder etc, but I have no idea how these monitors work. I am under the impression that it could potentially be a capacitor, or even simply some bad connection. Should I just open it up and have a go? Any tips?

Pic: http://i.imgur.com/ImI9tRV.jpg

Usually forget to take a pic when PC first starts up, so excuse the peek into my Youtube habits. I have noticed its slightly darker on that side even when the circle is gone.