I'm using kitkat 4.4.2 14.3.A.0.757
Hi, I'm using Z1 C6903, now the home and recent apps button on my phone is not working, I pressed but nothing happen, same with the lockscreen, even I set to PIN lock, after I unlock the screen, there is no PIN lockscreen, so my phone cannot be locked. I clear dalvik cache and wipe cache partition in recovery, but the problem did not disappear. How to fix this? Even in safe mode the button is not working too.