Monitor starts flickering when playing games.

[JohnCarmichael]

Hello everyone. I've got this weird problem with my monitor. It's an 'old' monitor but it still holds up (up to this point it seems). After I upgraded my motherboard recently (to an Asus P8H77-V LE) and the PSU (to a Corsair CS 650M) I'm having some issues with my VGA LG 22 inch monitor (1920x1080). I had this monitor for about 5-6 years, never had any problems with it.
The issue is whenever I enter a game (BF4, GTAV, etc) the monitor starts to flicker like an old TV would if there is any Interference of some sort... if that makes sense. The flicker is horizontal and blinks real fast, it's very noticeable, you can't really play these games like this... The thing is, if I turn on the Vsync, it gets way better but still noticeable. If I alt-tab the game the interference is still present on desktop, internet browser etc. Only after I exit the game completely the interference stops. It's not the video card (at least the HDMI port) because I have an LED TV Philips (1920x1080) 37 Inch via the HDMI port which looks Cristal clear while the monitors is flickering like hell. The LG monitor is hooked up via the DVI-I port with a VGA to DVI-I adapter. I know its ancient and analog and I should change it... but till then, is there any solution to this?
In screen resolution options, the monitor is set tu 60hz, as well in BF4 and GTAV. I never had this problem before I upgraded the motherboard and the PSU. Any ideas?
My rig:
Intel Core i5 3550 @ 3.30GHz
8.00GB @ 1600 ddr3
Asus P8H77-V LE Motherboard
GeForce GTX 770 @ 2gb
Corsair CS 650M Power supply
Win7 sp1

[noisebomb44]

Sounds like a driver issue

Try running the game in borderless window mode

If the flickering stops while using borderless window mode, try using DDU while in safemode to clean your graphic card drivers

 

Also

It could be your VGA cable being old since there are plenty of people with flickering problems which have fixed it by replacing their VGA cable (with a new one)

https://www.google.se/search?q=VGA+flickering&oq=VGA+flickering&aqs=chrome..69i57j0l5.1953j0j7&sourceid=chrome&ie=UTF-8

See if yours looks like the one shown in the videos

[JohnCarmichael]

I just tried running GTAV in borderless window mode and its worst, the flickering is more intense and visual.

EDIT

I forgot to mention my friend just bought a brand new PC similar to mine with a brand new benq 1080p LED 22'' monitor and he has the exact same problem. His monitor is also hooked up via VGA>DVI-I port. It may just be the VGA all together, he's now on his way to buy a HDMI cable to replace the current VGA connection, and we'll see if he will still have the issue, unfortunately, I don't have any other ports except for the VGA one on my monitor...

Second EDIT

Solved, seems like the problem is the power outlet. I tried hooking the monitor alone to a different power outlet and the flickering stopped. Looks like the power supply is more demanding and drains more power from the wall... Thats why the monitor does that, I'm not sure if this is normal, probably not.