Brother MFC-9420CN Service Manual page 64

(4) Sensors
No.
1 Paper Size Sensor PU
2 Registration Sensor PU
3 Fuser Exit Sensor PU
4 Tray Empty Sensor PU
5 OHP Sensor PU
6 Toner Density
Sensor PU
7 Transfer Unit Sensor PU
8 OPC Marker Sensor PU
9 Toner Sensor PU
10 Waste Toner Sensor PU
11 Temperature Sensor
for Fusing unit
12 Output Tray Full
Sensor PU
13 Toner Key Sensor PU
14 Room Temp. Thermistor
Sensor PU
15 ADF Rear Sensor
16 ADF Front Sensor
Name Code
PSU
PT1
PT2
PEU
OHP
TDS
TBS
PBS
TPD/TTR
WTS
(LED/TR)
PFUL
TNK
RTS
3 - 3 0
Photo sensor to detect the paper size.
Photo sensor to detect the paper is fed
from the paper tray.
Photo sensor to detect that paper is exited
from the paper exit unit.
Photo sensor to detect if paper is loaded
or empty in the paper tray.
Photo sensor to detect that material in the
paper tray is OHP.
Photo sensor to detect the toner density of
images formed on the transfer belt
surface.
Photo sensor to detect irregular rotation
of the transfer belt.
Photo sensor to detect the connecting
position of the OPC belt.
Photo sensor to detect if the toner is
empty or not for each toner cartridge.
Photo sensor to detect that the waste toner
bottle is full of waste toner.
TH Thermistor to detect the fuser
temperature.
This is the sensor to detect that the paper
exit tray is full of exited papers.
To detect the availability of key to be
provided to the toner cartridge.
Sensor to detect the ambient temperature
of the machine setting location.
Sensor to detect the document length, and
that the document is sent to the ADF.
Sensor to detect that the document is on
the ADF.
Function
Confidential