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3: Operation
3-8
Colorwriter LSR 2000 Printer
Service Guide
Figure 3-4
DC controller input/output signals (2 of 3)
Fixing unit abnormality
detection circuit
The voltage decreases as the fixing
roller temperature increases.
Fixing roller
temperature
detection
TH
"L" to turn ON the fixing upper heater.
+24V
SW1
SW2
POFF
PCONT
DOPN
"L" when the power switch is ON.
"L" to turn ON the printer.
FXSTS
SFSNS
/FXUON
/FXLON
THI
/FXSNS
Fixing upper heater
H1
Fixing lower heater
H2
/FXROF
/FXENB
Relay
"L" to turn ON the fixing lower heater.
The fixing heater can be turned ON
when pulses are output.
"L" to turn OFF the relay.
"H" when the safety circuit turns OFF
the relay.
Safety circuit
+5V
+5V
"L" when the fixing unit is properly
installed;
"H" when improperly installed;
pulse signal when fixing heater is ON.
"L" when the fixing unit is installed.
Thermoswitch
TP1
TP2
Thermistor
Power supply
Mechanical
controller
PCB
Fixing unit
Power supply control IC
Door
switch
Power
switch
"H" when the front door, pick-up door,
or fixing unit door is open.
J101-6
-5
-7
J112-31
-30
-28
-29
-27
-26
J112-22
J112-24
DC controller PCB
Thermoswitch