Brother HL-4200CN, Service Manual

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III-43
•
Error mode
Any error was detected in the printer.
•
Initiglizing mode
New parts have been just set to the printer (initializing with a new PHD).
•
Checking Unit mode
Printer is under checking consumable units.
7. CONTROL
7.1 Control of Paper Size
"ON/OFF of paper size switch of switch ASSY size " and "Diag tool indication data" are
shown in the table below.
Note:
Paper size switches are indicated as SW1, SW2, and SW3 from the above one.
Paper size switch
Paper size
SW1 SW2 SW3
Diag
indication data
LEGAL14" ON ON ON 00
LEGAL13" ON ON OFF 01
EXECUTIVE ON OFF ON 02
B5 ON OFF OFF 03
A4 OFF ON ON 04
LETTER OFF OFF ON 06
A5 OFF ON OFF 05
No cassette OFF OFF OFF 07
7.2 Selective Control on Paper Pick-up Unit
When not controlled by the printer controller, paper pick-up unit selected at the time of
turning ON are as follows.
Note:
The paper feeder by the paper tray under the printer is called "Tray 1", and the first tray
and the second tray in optional tray unit are called "Tray 2" and "Tray 3" respectively.
7.3 Scanner Light Quantity Control
The image data are entered to the laser diodes in the scanner ASSY as electric signals
(data are expressed with high and low voltage values), and the laser diodes convert the
image data from electric signals to optical signals (data are expressed with blinking laser
beams).
Variations in light quantity of laser beams or variations in optical system (such as lenses)
or drum sensitivity cannot attain proper electrostatic image, and accordingly the laser
diodes monitor the light quantity of laser beams to control the light quantity so as to
attain stable and proper electrostatic image.
The scanner in this printer has four laser diodes for yellow, magenta, cyan, and black
respectively, and the light quantity is automatically adjusted for each color.