Wired Intelligent Edge

I have one NBX 2102 phone that will not pick up a line when it goes offhook.

All my other 2102's pick up.

Is there a setting somewhere to do this? 

I have reset the phone several times.

This is on a NBX 100 R6.0.63

It's possible the hook-switch has failed. If you press the speakerphone button, does it seize a line? If so, the mechanical hookswitch in the phone has failed.

Thanks. I overlooked that entirely. 

If the switch hook has failed you can open the phone and clean the contact with a pencil eraser. This works most of the time and will save you a phone,