I can't really assist in this process. My official recommendation would be to get your unit inspected and repaired by a qualified service technician. It could be a very simple fix.
The hole in the first picture is a standard hole for a cable lock. So for instance, if you wanted to attach your monitor to your desk so nobody can steal it, this would be where the cable lock goes.
The second picture... I just can't identify that.
Recently my monitor has been acting up. When I turn it on, it doesn't stay turned on for more than a second before the screen goes black (even though the green LED is still lit). After a few tries of turning it on and off, it eventually stays on. The same thing happens if I change the monitor settings (I have dual monitors to see what I'm changing).
So I've googled it and I suspect it's a capacitor problem. So I want to change the capacitor but I can't get the thing open. I even looked at the manual but it doesn't say anything, and I can't find it on google.
I removed the stand, and unscrewed everything. I see a small hole with a picture of a lock but I can't figure out what to do with it. And there are two more holes in the middle. I've pressed down on them, maybe not hard enough? Do I need a special tool? I provided pictures below. Please help! Thanks in advance.