Broken volume keys

[nischal shrestha]

I have a l 620 and my volume up and down keys a not working, how can i fix it or is there some app I have Lumia cyan update

 

[ven07]

A lot of users have had issues with the volume buttons on the 620....

List of viable options:
Search results for "volume control" | Windows Phone (United States)

Edit: if your warranty still covers it, then bring the phone in for a replacement of so they can fix it