Whats going on?

[Android Central Question]

My samsung J7 works fine untill it suddenly goes to the lock screen on its own and starts blinking a few times before blacking out completely.
while blacked out, it can recieve calls and messages, (i can feel it vibrate).
a quick reboot brings it back but it happens all over again after a couple of seconds.

if left untouched, in a couple of hours everything is back to normal.
and happens again the next day

is it a system error? caused by excess storage? help?

 

[Rukbat]

Not caused by "excessive storage". Try starting in safe mode:

• Turn the device off.
• Press and hold the Power key past the screen with the device name.
• When 'SAMSUNG' appears on the screen, release the Power key.
• Immediately after releasing the Power key, press and hold the Volume down key.

If it still happens, it could be a corrupt system - then read [Samsung] How to flash Stock ROM via ODIN.