I think I have actually found out where exactly the Surface overheats. It's on the very top left on the front where the audio jack is located (on the black border itself, not the screen). I put some flat metal in the freezer and as soon as I put it on this
spot the flickering stops after about 10 seconds and comes back just as quick when I remove the cold metal. If I cool any other place the flickering won't stop.
Can anyone try this as well?
I did the test and bingo, the top left corner is the key. I used a small ice cube surrounded by a plastic sheet. The flickering stops immediately when the ice cube is in contact with the top left corner and starts again a minute after removing it.
Important finding! Good job.
Interesting...so I'm thinking one of 2 things:
The heatsink is drawing a lot of heat, more than it can cool (I wonder if maybe our models all have a fan in that top left area that could have failed?) which is heating the screen and causing the flicker
The audio hardware is overheating or overvolting and causing the issue
I've tried disabling the audio hardware in the UEFI and I'm running prime 95 with the seconds turned back off in my system clock. I'll update if I can induce the flickering, which would rule out audio hardware being the cause and leave us with a heatsink
issue. Those of you having the problem on SP4, do you have an i3, i5 or i7 model? Do you know if your model has a fan in the top left? (I don't believe i3 does but I think i5 or 7 might)
EDIT: I ran prime95 and disabled the audio hardware and the screen shaking is still occurring, so I think what's happening is you're cooling the heatsink.
I noticed my screen is significantly hot in that top left area around where the heatsink is.
Here is an image of the i5 and i7 models that have the hybrid cooling system. The top left is where the fan is. It looks like the fan may be failing, cooling the top left corner is offsetting the work of that fan. Either that or something is creating
more heat than the system is meant to offset and cooling it is helping.
Either way I think we can safely say this is an overheating issue. Great find