Resetting the flash firing settings to the factory defaults
You can reset the current flash firing settings retained on this flash unit to the factory defaults.
For the setting items and options available for the flash firing settings, see “List of flash settings.”
Make sure that this flash unit is powered, and then press and hold the LEVEL - button and the LEVEL + button simultaneously for 3 seconds.
The TEST button and the LINK lamp light in red, and then the flash firing settings are reset to the factory defaults.
While the reset process is in progress, do not turn off the power to the flash unit or remove its batteries.