S3 screen unresponsive

[Bonose]

I have att S3. The screen becomes unresponsive at random times. I have done factory reset and wonder if it's a hardware problem. Power home and volume buttons ok. It works for minutes then can't be used. Store reps no help. Return and options at screen bottom usually ok. No unusual drops on hard surfaces and have decent rubber case. Have to take battery out to turn off.

Help

 

[gordonfink]

When it works, it works all the way, and when it doesn't work, it's totally dead?

Could be a loose cable connector.