Default [Q] MK808 Blank Screen Error after few minutes?

I am using MK808 Stick with my 46" Samsung LCD TV (connect by HDMI cable).
I tried some custom firmware as Fineless 2.1, Hydrid 2.2.4 but it had the same problem:
After first booting and go into Launcher screen, I config all preference in settings about "Time and Date", "USB Debugging", "Google Account", HDMI output 720p (60). But when I run Google Play, it will be blank screen (grey) and freeze. I reboot by unplug and replug, but the problem still happen (freezing after few minutes using). Anybody can help me?
Now I am using Fineless 2.1 (720p kernel and boot).