Brother HL 1240 - B/W Laser Printer Service Manual page 248

This LED also works as the Toner LED with the Alarm LED. They blink
simultaneously to indicate a toner
in Chapter 3 .
LED
Drum
Ready
Paper
Alarm
Toner
Data
Blinking every 5
seconds
Drum
Ready
Paper
Alarm
Toner
Data
error. See "How to replace the Toner cartridge"
Error Action
Toner low Indicates that the toner cartridge is
nearly empty. Purchase a new toner
cartridge and have it ready for when
Toner empty is indicated.
Toner empty Replace the toner cartridge with a new
one referring to Chapter 3.
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