end of April (about 22nd) upgraded to Android version 8901.4.A.0022.0
April 24th (Tue) screen starts showing screen-wide flashes of discoloration when touching on photos in WeChat and artifacts (flickering clumps of pixels in a lattice-like pattern across the screen but only on the photos never the UI) when swiping between photos in WeChat
April 28: strong flickering, discoloration when viewing and touching on photos in signal, WeChat, Simple Tools Gallery, Chrome, Firefox and even Google maps (with satellite overlay enabled). Screen sometimes continues to flicker without touching it. Android UI and other “computer graphics” never flicker or cause flickering.
Behavior seems to be triggered by viewing, touching, swiping and zooming photos in various apps. Behavior disappears after a while and then reappears.
It doesn’t appear to be the screen as you say it doesn’t happen in normal GUI use.
So to clarify, does it happen when you touch the screen generally, hence the idea of a contact issue?
When you tighten the screws ensure you do not tighten to much as that can cause distortion if everything is not ‘flat’
You may want to check the pogo pins are all movable, too much tightness may disable one so when you press on the screen it may upset some pins.
There are also five grounding contacts. When you remove the display module and reconnect you may find
a) they are not clean and do not create a good contact between display and main board
b) If the screen malfunctions with even a light pressure then it may be a capacitive issue and dampness could be an issue.
Grounding contacts that may benefit from cleaning, also check the spring contacts on the core module are raised enough
Try using the phone in safe mode to eliminated any custom app issues.
As you don’t have an SD card check how much memory you have, even 10Gb isn’t a lot, and check the RAM usage maybe
I have about 0.9 GB of free RAM and a bit more than 8 GB of free storage space. I will restarting in safe mode tonight and then try reseating the display.
I did not to my knowledge overtighten the screws.
The artifacts (pixel clumps) start when looking at photos and the flickering starts or is most pronounced when touching the photos (eg to swipe). You are right, an issue with the screen itself does seem unlikely given that the UI doesn’t flicker. It rather seems like some graphics driver issue…
It is not bone-dry here currently but also not damp. And the issue has been going on over several days in different environments