Har! Manitoba to PEI? Wow...worse to worsererer
My uncle and a few relatives moved out there 30 years ago...was a prof out there for decades... now ..dean of medicine at dalhousie ...great guy.
Ya you're getting proper snow eh?...Like when I was a kid...couple winters we had snow up to the roof and higher...last 30 years have seen none of that...pity too. Ach...climate change....

Anyway ...back to the imp stuff here.
I didn't think it was screen protector issue frankly.
Since I have them on all my n8x0 devices and never had that kind of prob. nor had the prob on my n900...mind that isn't to say it can't happen...seems like such screen problems at worst would be related to severely worn out/reallllly used... tactile screen sensor issues. But I don't think that is the prob. here for you
You don't need schematics to tear it apart and all.
Less invasive, time consuming, and brain-eating is aiming at the most likely prob. first and narrowing it down from there.

Just reflash the device(reinstall the operating system)
The process may seem convoluted and time consuming if you have never done it...but the entire process from plugging it in to finish takes a couple of mouse clicks...and 2min tops waiting for the operating system to reinstall.

Just get a usb male to micro usb male cable...(if you don't have yours that came with the box) ...the tiny port on the right side under the stand is for the sucker.
grab the latest n810 official nokia diablo firmware ...and the nokia update wiz. (assuming you use windoze) (also if you don't have copies they are accessible from members) and away you go...it is easy peasy...need any help just shout