Galaxy S4 I9505 Turns suddenly off

Hello , i have a Galaxy s4 ( i9505 ) with a problem that it turns it self off randomly , sometimes i can navigate in the menu , even start for example youtube aplication listen to music etc , but the phone just turns off randomly .

Ive done the following :

1) Changed firmware from 4.4.2 to 5.0.1 , and even backwards
2) Put factory firmware with 4 files and .pit
3) Tried it with 3 different batteries charged to 100%

Still no luck with the phone , can this be related to EMMC memory problem ?
Or is it something else ?
If someone had the same problem and will be kind to reply i will thank him , thank you !