iPhone shuts down after 15sec on Apple logo

Hi,

My iPhone 5C suddenly shutdown with no apparent reason.

I click the power button and the Apple logo shows for about 10 to 20 seconds and after that it disappears. I click the power button again and the same thing happens..

The battery is fine and working properly...

When I plug it to the PC iTunes doesn't detect the phone.

I enter DFU mode and iTunes detects the phone and says there's a problem with the phone and it requires and Update or Restore (most the times this screen doesn't show, just the Restore option)...

I Restore the iphone and it works fine.... After a few hours of using it, installing the apps again and setting the phone properly, it shuts down and it the same thing all over again...

What can be wrong with the iPhone? Is there any app, software, key combination the make a full check on the phone's hardware?!?

Thanks,

Pedro