Default [Q] (Q) Screen Randomly Switch Off

Hi everyone,
I have problem with my android tablet, the screen will randomly switch off and back to lock screen even when i'm using it play games or watch movie. Even when i put the screen to "never" sleep, this issue still happening.
I already try to do factory reset and this issue still happening.

My tab (iFive Mini 3GS) using MTK MTK6592 Octa Core 1.7GHz, and already using android 4.4 KitKat

is that the problem on the device or maybe the system?

Can somebody please help me with this issue? cause this so much frustating.

thank you