My android phone keeps turning on and off help?!

[xxxforeverxxx]

my galaxy s3 has turned off by itself maybe around noontime, its now 6 pm, and all its been doing since then is turning on halfway, then stopping. then does the same thing over and over again. im even charging it and i have to hold the power button for a very long time before i can see the charging symbol, and its around 50% but the phone itself wont turn on! help please??

 

[Ravi Gagan]

Stock rom need to be reinstall
Take it to the service centre and they'll install latest firmware and will detect additional hardware problems if present

 

[gavi7566]

have you tried hard resetting the phone? if not, it can resolve your problem.