I've a Kenwood Mask Unit that refuses to flip back over. I can hear the motor whurring as if it is trying but stuck. Consequently I can't access the panel controls or remove the face... any ideas?

Yes, try removing any final plastic trim bit (on the extreme outside of the head unit's front) and inspect the metal. If this is bent, because you've pushed it in when installing it, then it'll cause all sorts of problems. Try GENTLY levering it out to make clearance if you can...

ditto - this solved it on mine to

Situation resolved...

Removed the plastic trim etc but that didn't work, so I had to disconnect the power lead from the back of the unit. This worked and the face then flipped over. Had to then use the mask key and reconfigure my settings.

My conclusion was that it wasn't jammed as such but needed to be reset. The unit had previously been working fine for over 2 months.

If it happens again, I will remove the main fuse to reset it rather than remove the unit which is a pain.

That's a good tip to know, thanks for the update :)