The indicators light and flash to indicate the printer's status. The following symbols are used in this FAQ to explain the meaning of the different indicator colors and patterns.

/ / /	Indicator is lit in the color shown
/ / /	Indicator is blinking in the color shown
/ /	Indicator blinks 1 or 2 times in each color, then turns off
	Indicator is lit or blinking in any color or pattern
	Indicator is off

POWER	STATUS	BATT (BATTERY)	Bluetooth® Wi-Fi®	Description
				Power on
				Roll cover open
				Receiving data Transferring data
				Error Print error Feed error Cover open error Communication error Image processing error Database search error No template error Access point search error Access point connection error Security error >> See below for more information
				Error Battery error Mass storage error
				System error
				In boot mode >> See below for more information
			(Once every 3 seconds)	Wireless on, not connected (RJ-4040 only)
				Wireless or Bluetooth on, connected
			(Once every second)	Now setting WPS (RJ-4040 only)
				Now resetting
				Formatting complete (When [Print Data after being Printed] is set to [Erase])
				Now cooling >> See below for more information
				MCR read mode
				MCR read success
				MCR read error
		(Once every 4 seconds)		Rechargeable battery power: half
		(Twice every 4 seconds)		Rechargeable battery power: low
		(Once every second)		Battery must be charged
				Charging
				Rechargeable battery power: full Charging complete
				In mass storage mode
				Processing file in mass storage mode
				Initializing

Indicator Warnings

The POWER indicator does not light

The printer is receiving no power.

If you are using AC or DC power, make sure that the AC adapter or Car adapter is properly connected and make sure that the AC or DC power outlet is turned on.

If you are using DC power, check the fuse.

Head or motor is cooling down

The thermal head or motor is too hot.

Head:
If the thermal head becomes even hotter, the thermal head may produce imaging on the paper in areas not intended to be printed. This condition is normal when printing documents with a great deal of “black” content.

The printer will stop and resume printing after the print head has cooled down.

To avoid or delay the onset of this condition, print using a lighter density setting, reduce the amount of black space being printed
(for example, remove background shading and colors in graphs and presentation documents), and make sure that the printer has adequate ventilation and is not located in an enclosed space.

Motor:
Do not use the printer continuously. If the printer is used continuously, the motor will become too hot. In this case, the printer will stop and resume printing after the motor has cooled down.

Data reception error

Data may not be received correctly when communications are unstable. Try connecting again when communication conditions have improved.

Printer is in boot mode

The AC adapter was unplugged while the firmware was being updated, and the printer started up in boot mode the next time it was started.
Contact your reseller or Brother Customer Service for assistance.