Tone reacted to JohnB1952 in XT4 Q button
PROBLEM SOLVED RE Q button
I noticed a small yellow padlock displayed on LCD which is active when "controls have been locked"
To use this lock feature press and hold the Menu/OK button to activate and/or deactivate.
I switched it off and the Q button now works !!!!!!!
How it was switched on is a mystery to me but at least Q is now working.