No Sound On PLayback

Suddenly no sound on playback in audacity. Irrespective of file type etc. Volume & gain sliders all up and playback level indicates that there is sound but nothing comes out of the speakers (or headphones if they are plugged in). Sound works normally on all other applications (Windows Media Player, Chrome, VLC etc). Re-installed Audacity several times. Same problem. Any advice?

Up in the tools there’s a speaker symbol with a slider. Is the slider turned up?