Is the built-in AF-assist illuminator item set to [OFF]?
The AF-assist illuminator does not light if [OFF] is selected for Custom Setting “a” [Built-in AF-assist illuminator]. To light the illuminator, select [ON].
Check the focus mode.
The AF-assist illuminator does not light in the following focus modes: AF-C (including when AF-A is selected and the camera is shooting using AF-C) and MF.
Is the camera in video mode?
The AF-assist illuminator does not light in video mode.
