Freezes while opening Lock Screen
hey i have some problem with my galaxy s4 i9500, so here's the story : i've got some weird burn n reddish screen on my s4,, then i bring my s4 to the service center,, they had replace the screen for 4 times but still have that issue, then they say,, they going to replace the screen 1 more times but now with the mainboard. okay after 2weeks my s4 reddish screen fixed.
but now i have a new weird problem, everytime i try to unlock the phone ,, sometime it hangs ./ freeze,, and when i tap the power button or home button several times, it reboot itself. now im completely frustrated with my s4,, anyone have any tips to fix this lockscreen freezing? i already try to factory reset it and reinstall the firmware. anyone please help