Help S4 Major Problems - Shuts Itself Down

[Ryan007]

So Going back about a month my S4 began to shut itself down by itself sometimes, not very often and I could turn it back on no problems, as it has gotten more recent it has began to go off for about an hour then randomly just boot back up, while it is turned off (by itself) it will not charge or connect to the computer but when it's not playing up it charges fine. Recently (this week) it turned off and I could not get it back for the rest of the day until night but the next day it was completely off. I've swapped the battery with another S4 one with no luck, I've tried doing soft resets and clearing its catch partition so I went out to town to get some help, went to a few places saying I need all different things so basically nobody has a clue what the problem is, some said it is its software some said hardware and it needed flashing but today (a few days later) it is back on again so I'm not getting it wiped of my data when it clearly works fine. Another said it needed a new charging port but I've just charged it fine. I need some professional help on this one, I can't have it go off for a few days at a time. Also tried updating but its fully up to date. It is 100% not water damaged and its not been dropped. only got a few scratches here and there.

Any help is much appreciated.
I have no idea if this post is in the right place sorry if not

 

[vjmariano]

my first thought would be to do a full system restore and start from scratch. Mine was doing the same thing but not to the extent yours is and I was told a battery so I replaced it to no avail. then I tried on my own to reset the phone completely and it worked I was told I must have downloaded a virus. hope this helps

 

[Ryan007]

Could you recommend a way to backup apps and their data, I have a lot of apps that keep me going but if I restore I have to start again with a lot of them. Pics are all fine got dropbox