Alienware 17 2013 (Ranger) weird screen issue.

Hey there , few months ago I posted here regarding an issue I had with my screen.
(It's the 2014 model with an 880m and an Intel i7 4910)

Up to this day , I still haven't found a solution to it. (I cannot find a motherboard replacement and countless local shops have failed to fix the issue.)

So basically the issue happened while I was gaming , the pixels started flickering (red/green/blue) as it can be seen in the picture I posted below. I currently have a temporary solution , I had to force down the refresh rate to 40 Hz from 60 and the problem is "solved" (well not really as you can still see the pixels flickering if you look very carefully , just nowhere as bad as it is on 60 Hz)

I've been trying to find a motherboard replacement but meanwhile I'm hoping that some of you might have a suggestion that I could possible try.

Here's what I've done so far : I've replaced the LVDs cable twice , I've replaced the entire screen , I've tried running the laptop with 1 graphic card , I've tried a completely new graphic card but nothing has solved the problem. Using an external monitor makes the problem vanish so I assume that a bad GPU is not the case. According to Dell there might be a burned transistor(?) on the motherboard.(they suggested a replacement but there's no stock) I've got no idea what that is and if it's fixable.

Any help/suggestions would be highly appreciated.

If someone also knows why the flickering happens only while on 60Hz and not on 40Hz please let me know.

 

I would replace the motherboard.

They still run about 200 USD on ebay.

 

Have a new one for sale. If interested - PM me.