Flickering laptop screen when hot - cause?

What could be the cause of a flickering screen every minute or so like the picture below?

• Flickering seems to get worse when hot (usually into an hour of gaming CPU 100C, GPU 85C max).

• Adjusting the laptop screen or even tapping the laptop while flickering stops it.

• I recently disconnected and reconnected all the circuits in the laptop for cleaning.

• Laptop is a bit more than 3 years old (Acer Aspire v3-471G).

I am hoping the cause is due to loose cable connection not GPU. I think that's likely as my laptop also flickers when I am in Desktop ie even when not using the NVIDIA GPU (it has integrated intel too).

If that is true then the problem is how to open the laptop up again because an important screw has lost its grip...

Any advice is appreciated.

EDIT: Screen still flickering when at 55C (normal temp)

EDIT2: Adjusting screen when not flickering causes flickering as well if I hit the right 'spot'.

Solution 1:

For the readers in the future. About 5 years ago (2015) I had the same problem with my 5 years old n5110 core i7 with a powerful gpu both on the same heatsink.

It is absolutely your thermal grease or thermal pads. They are not transferring the heat well. Thermal greases will not lose their natural chemical effect during time but they get stoned and stone is easily fragile making nano threads of insulating air by any tiny shocks.

I'm still using my 10years old n5110 for software development and gaming.

The important note is : the thermal pads can be torn easily when we loose and fasten a heatsink again (they lose their shape by pressure like a memory foam) thus even if CPU and GPU are greased well the motherboard's chipsets may be hot too.