Mitel 5212 IP Phone "dnd system" Questions

...phone that refuses to ring. The ringer volume is all the way up and the speaker works. Anyone have any ideas what I should check? Is the phone forwarded? is it on DND? What system is the phone

Mitel 5212 handset. Thanks hit the blue button (Superkey). hit no until you see DND and you can turn it off or on. If you don't see if you have to login to phone system and get feature access code

Is there another way to put it on dnd?? I do not have a softkey for the dnd feature. yes, ask system admin for *code to dial