Zoom H4next Operation Manual page 21

* shut down screen
HINT
AMP
OFF
Mixer H4n Instruments
OFF OFF OFF
The H4n features a HOLD function to make
any button operation inactive, preventing errors
during recording.
To engage the hold function,
slide switch to hold position.
* 'Key Hold' display
If you press any button while the HOLD
function is engaged, the screen will display
"Key Hold" for two seconds. To disengage
the HOLD mode, slide power switch out of
hold position.