Brother HL 4570CDWT - Manual (Page 72)

Control Panel
66
3
LEDs
3
The LEDs are lights which show the machine status.
Data LED (Green)
3
Error LED (Orange)
3
LED indication Meaning
On Data is in the machine memory.
Blinking Receiving or processing data.
Off No remaining data in the memory.
LED indication Meaning
Blinking There is a problem with the machine.
Off There is no problem with the machine.