Touchscreen problem after 5.1.1 update?

[Freelancer2]

I updated my Z3 Dual to 5.1.1 Build 23.4.A.1.200 (Hong Kong) a few days ago.  I found that my touchscreen has some "dead zones" when playing games or typing on the keyboard, mainly a vertical line about 2cm from the left of the screen and also a bit on the lower right.

I wonder if this is software related?  I have already tested the touchscreen using YAMTT.

[xavinux]

Hi @Freelancer

Please, first run a backup of the device information as explained here. Then perform a system repair using PC Companion or Bridge for MAC. This will factory reset your phone and erase all data. You might need to charge your device for about 1-2 hours before so the device has at least 80% battery. Make sure the device is not connected to computer or laptop and turned off until you are prompted (sometimes you have to press power button and volume up until the device vibrates 3 times or on some devices you have to press the small button near the SIM tray or on the back of the device). Start PC Companion -> Support zone -> Update my phone/tablet -> Blue Repair my phone/tablet -> follow instructions. When prompted connect your phone still switched off holding volume down or back button. The repair or reformat process will start. If you are using Windows 8/8.1 or a 64 bit operating system adjust settings for PC Companion and run in compatibility mode -> chose Windows 7 or XP.Keep us updated please, I´m at disposal for any question.

[Qatrium]

You can run a diagnostic test from here: Settings -> About phone -> Diagnostics -> Test -> Touchscreen

[Freelancer2]

Well I can pass the Touchscreen test under About Phone. But if I use *#*#7378423#*#* to enter service mode and do the touchscreen test, when I try to draw vertical lines, some lines are broken or auto "skewed" to the left or right.  Horizontal lines seem basically ok.

[Qatrium]

Do you use a phone case with magnetic closure? Or battery bank case?

[Freelancer2]

No, I just use a simple plastic back cover.

[Qatrium]

Did you try to test it in safe mode?

[Freelancer2]

Yes I did try in safe mode, same.

[Qatrium]

Strange it passed the Diagnostics, which may rule out a hardware issue. Are you willing to re-install you phone software? This will wipe your phone's internal memory and should clear out if it's software or hardware issue. Follow Xavinux's guide on 2nd post: Backup, perform Software Repair with PC Companion and hopefully it will be resolved if it's a software issue.

[Freelancer2]

I think the Diagnostics Touchscreen test is a bit "simple" since it just requires me to wipe the screen, but I can do that despite any "skipping" when I draw a vertical line.  But if I open Sketch and draw vertical lines at the problem areas, the lines appear broken or skip to the left or right.  That affect my keyboard typing or playing games.

I might try the backup and software repair later at night.