How do I stop my S3 switching off?

[AC Question]

I thought my Galaxy S3 was running too high on the RAM (always around 750/830, very slow) so I deleted as many unnecessary programs and tried to stop a few apps running etc. I must have disabled something I shouldn't have because now my s3 shuts down after an hour or so of sitting idle. It usually drains the battery too.

I have tried a new battery - same result - shut down if left idle. I then did a full restore (wiped everything - back to scratch). Same thing happened - shuts down after an hour or two.

One interesting thing that I worked out, - if I leave an internet radio station playing it wont shut down ( I did this for two days straight as an experiment)

Does anyone know what this problem could be? I have been googling help for two weeks and putting questions in forums. No response yet? I need my phone for work and I cannot afford a new one at this stage. desperate! thank you

 

[Rukbat]

I thought my Galaxy S3 was running too high on the RAM (always around 750/830

That's how Android works - unused RAM is wasted RAM. This isn't Windows.

Does anyone know what this problem could be?

You deleted a file the phone needs in order to keep running. If you have everything backed up, you just flash the stock ROM back ([Samsung] How to flash Stock ROM via ODIN) then restore the backups. If you haven't backed things up, play an internet radio station, so the phone will stay on, then see Backing up an Android Device.