Yongnuo YN560 - Sound Signal

The
meaning of
[
Sound
signal
]
Sound Meaning Operation
2 beeps a. The sound signal is enabled;
b. The flash is started;
Normal
3 beeps The flash is in the charging state Waiting for the
completion of
charging
4 beeps The sound switch is now disabled Normal
Continuous beep There is insufficient power and
the flash will turn off
Replace the batteries.
A long beep The flash light is fully charged,
and can be used.
Normal