Mi4c Issues After 14 Months ?


Jan 8, 2016

I was a proud owner of mi4c 3/32gb from 10/2015 until few days ago when my new mi5pro arrived. Of course, I was using xiaomi.eu roms. Nevertheless, I gave 3/32gb to SWMBO and put her 2/16gb mi4c bought in February to sale.
Yesterday, first the screen went of on her work close to noon. I was remote assisting, so all I could conclude it was screen of and device itself was working, even after restarts.
Screen went on finally after she managed to enter fastboot. Great, LCD is not dead. Then earphone icon went on, obviously and You could not use phone. I told her to clean it, blow the dust out etc... nothing helped. Screen went crazy, writting and clicking by itself. Earphone icon went out by itself when we were driving home, but digitizer was still crazy....

When I finally got phone in hands first I reflashed (again) latest stable, cleared caches few times and then saw huge battery disagreement between TWRP (13%) and android (1% but working). Before restart android was 53%. WTF?
I tried to squeeze the juice out of the battery as much as possible leaving video player on,
- turned device off
- took sim cards out,
- gave a device pretty good air pressure blow thru all possible holes
- put it on charge for several hours
- charger off at 100%, device on (20% drop), device off, charge... and repeated until I got like 3% difference.
Before all that I checked xiaomi's screen digitizer test and it was fine.

So, I used air pressure to blow inside phone as a 'redneck procedure' to remove possible dust and maybe slightly move or totally disconnect all flat cables without actually opening the phone. The most efect was done blowing into SIM card opening, cause I felt back case inflating.

Today it's working flawlessly. 16 hours off charger in use - 71% battery left, no screen/digitizer glitches.
I might assume in best case that some of the flat cables are or were loose....

So in one single day (yesterday) I got:
- LCD screen false failure
- Earphone false failure
- Digitizer false failure
- Battery false failure

Today, working like a charm, a new phone.

OR: Shall I start to worry, is it the worst case - a motherboard dying?
If it's the case, I assume then: it's a question of time (or next overheat) when it will become a nice brick....