HL-2030/2040/2070N SERVICE MANUAL
Confidential
8-3
1.2
User Maintenance Mode
This section describes what the user should do when replacing the consumable parts.
<Resetting the drum counter>
The printed image may deteriorate when using the drum unit to a certain degree. The printer
detects how much the drum unit is used with the drum counter and lights up the
Drum
LED
when the drum unit life is nearly at the end of its life to indicate to the user that the drum unit
life reaches the end of its life soon, in order to prevent the printed image defects due to drum
unit deterioration.
The printer does not provide the function which resets the drum counter automatically when
the drum unit is replaced with a new one. If replacing the drum unit with a new one without
resetting the drum counter, the counted value of the old drum unit is used continuously so
that the
Drum
LED is not off.
When replacing the drum unit with a new one, it is required to reset the drum counter
following the steps below:
(1) Open the front cover while the power supply of the printer is ON.
(while the old drum unit is being installed in the printer)
(2) Keep the
Go
button pressed down until all LEDs on the control panel light up. (approx.
four seconds)
(3) Release the
Go
button when all LEDs light up and take the old drum unit out of the
printer.
(4) Install a new drum unit into the printer.
(5) Close the front cover and make sure that the LEDs are off.
<Initializing the developing bias>
When replacing the toner cartridge with a new one, the new toner sensor detects that the
toner cartridge is replaced, and the developing bias is initialized automatically. Therefore, the
user is not necessary to initialize the developing bias.
If replacing the toner cartridge which contains enough toner with a used one, the new toner
sensor cannot detect that the toner cartridge is replaced so that the developing bias is not
initialized. In this case, the print density may be lighter than usual.
Density transition
Bias voltage
Print density
Toner empty
[Used toner amount]
Dark
Light
Bias voltage when replacing
with a new toner cartridge
Density when replacing with a new toner cartridge
Bias voltage when replacing
with a used toner cartridge
Density when replacing with a used toner cartridge
In such a case, initialize the developing bias forcedly following the steps below:
(1) Open the front cover.
(2) Take the drum unit out of the printer.
(3) Press the
Go
button.
(4) Install the drum unit into the printer.
(5) Press the
Go
button.
(6) Close the front cover.
