[Bug] Screen goes black when in call

[srps]

I've been having this weird issue where the screen goes black when in call and I'm unable to do anything but simply wait for the call to end and the lock-screen to come up so the screen lights up again.

I'd noticed this happening randomly with the MIUI ROMs (rare case), but since I've enabled true dual boot it seems to happen only for the first call I do after reboot (on system one).

My problem is more on system 2, where I have the (sort of) stock android ROMs. If I flash QDT14 it seems to work just like the MIUI one, where the first call has a black screen and functions well for the rest of the calls, but every single other ROM (Mokee, Cofface's, GDroid) has the black screen issue and it doesn't go away.

I've already tried to disable \ re-enable true dual boot factory reset, wipe caches, reflash QDT14 and flash others over it and probably plenty of other stuff and I have no idea where the issue comes from since no one seems to have it.

Does anyone know what's going on?

 

[Staalborstel]

I've had this too, eventually I flashed it with miflash (full wipe), then installed miuiandroid ROM. This fixed it for me.

 

[srps]

Hm, but do you have true dual boot enabled? I only have the annoying issue in the system 2 (stock) with non-QDT ROMs apparently.

I'll try that anyway, how did you back up your data? I got authenticators and stuff I need to preserve, so I always keep a backup in CWM, but with the full wipe that probably goes away as well.

Nevermind, found out I can just use Titanium Backup for my needs. Anyway, flashed stock ROM back with fastboot, re-configured my stuff, re-enabled TrueDualBoot.

Again system 1 on MIUI had the black screen on the first call, but never again. System 2 after flashing Mokee and screen still goes black.

This looks like it's related to the proximity sensor, maybe in theory when it detects your face it goes black and disables all touch control so you don't accidentally hang up.

Thing is, my phone (in MIUI) never disables the screen even when it's on my face. Could the proximity sensor be malfunctioning and causing all this? It's weird that no one else has this issue.

Thanks for answering


Edit: It is the proximity sensor, it isn't working, so it acts as if the phone is always on the face, producing the annoying black screen.

Is there a way to disable proximity sensor functions or something? Xiaomi ROMs seem to just ignore the sensor reading and show the display all the time, while the 4.3-based ones try to use it.

Guess I'll need to research this as I want to test 4.3 ROMs, but the black screen sort of annoys me too much for my likings and I don't want to send my phone back to China as I don't have a replacement.

Edit 2: It might also be the screen protector, as it doesn't have a hole for the light or the proximity sensor. Since it isn't completely transparent it's possible that it's being blocked or something.

Still need to find something to disable it that works on 4.3, I don't use it anyway so...