Nano gen 5 stopped playing

Hi guys, I have a Nano 5 that was playing fine on a Sony dock. Now it just stopped playing.
The screen shows it going from play to pause. The Nano works on the clock radio and with ear buds. The Sony works with another iPod .
I have reset the nano but no luck
What can I look at?

Try cleaning the headphone jack with a qtip and clean the dock connector with compressed air. that might fix your problem.

Everything is clean. The ipod will work on another dock and my iphone will work on the sony. Makes no since