When i get an incoming call, most often the display is just a mess of individually coloured pixels, like on old television without signal but in RGB. Sometimes it is also tiled. Sometimes there are portions of a normal display, but heavily overlapped with different types of squares. I have also seen some parts of what should be there, mirrored.
I believe that in that case also the touch function is not working, i have never succeeded to answer it “in blind”.
I can press the top left physical switch and display turn black, and it usually works to wait a few seconds then clicking again to get a normal screen, but mostly it requires several trials so i miss most of calls…
When i have no incoming calls it mostly works OK, but sometimes when i click the top left physical button, the screen just flickers and get black, sometimes it looks somewhat like described above when answering a call. But here i can swipe up and hear a “plopp” like it got unlocked so touch works, but screen is black.
This started about three weeks ago. Seem not related to an update - former update was earlier IIRC, and the last update did not change this.
I have never seen screen go bad once it gets displayed OK initially; it is sometimes (seldom) go bad when waking it, once in three weeks when morning alarm goes on, but when answering a call it MOST OFTEN go bad.
I am thinking this may be an issue of power supply instability, as i see it only when powering up the screen, and even more so when there is an incoming call (radio + vibrator also use power). But it may also be some software drive initialisation of screen that fail.
I have dissassembled and wiped the screen contacts with a coarse paper towel, no change.
The closest similar report i have found is this, but it is over 9 months old: Weird screen behavior, fairPhone2 now unusable