Viewsonic XG2703-GS horizontal lines all over the display

[negodidentina]

Hello members of eevblog. I have a viewsonic xg2703-GS monitor that has seen quite a few years of usage. It's one of those monitors, 27inch with 144hz and 1440p. This one offers G-Sync as well. Due to unknown reason, a couple of weeks ago, horizontal lines started to appear on the screen. After testing singled out the problem to be the monitor itself and not my GPU or display cable. I'm typing this on that same system with a spare monitor.
It's almost a year after my warranty has expired  so when I contacted Viewsonic all they can do was looking up the parts numbers for my specific monitor so I can order replacements. I tried ordering parts but apparently Viewsonic US does not ship outside the US. So they told me to contact their branch that according to the support staff "supposed" to help me in this case. Viewsonic Netherlands replied me by saying that the responsibility to help me sits with the seller and not them. My seller was Amazon.
I've looked at repair shops in my location and none does pcb repairs. All they offer is parts replacement which I can safely say I can do that myself.
At this point I've decided to try and repair it myself. But I have no knowledge of pcb repairs, so I'll be starting at 0. I will include a couple of attachments to see if anyone can tell me what the problem is. Also I have no tools to diagnose a faulty pcb. My budget is not too high, probably with a new multimeter plus additional tools should sit around the 300 ballpark. Can someone recommend me the required tools to fix this monitor?

[tunk]

Probably won't make any difference - could you try to reseat the PCB with the heatsink a few times?
Ditto for the cable that goes to it (both ends).

[negodidentina]

Hi, Tunk. Thank you for the suggestion. I just have tried that. The pcb with the heatsink is the gsync module. I have removed it and reseated it back in place a couple of times but the symptom of my monitor remains.