Error Detection - Canon iR8500 Service Manual

9.7 Error Detection

The following are checked in relation to the fixing temperature control mechanism:
[1] Temperature control error by the main thermistor (TH1)
[2] Sensor error by the sub thermistor (TH2)
[3] Overheating error by the thermal switch (TP1)
J508B
1
M-TEMP
7
0V
8
S-TEMP
9
0V
10
20
Main
heater
J505A
1
MHDTC
10
MH-ON
11
0V
12
13
14
15
16
100/200V detect
17
When '1', the main heater goes ON.
J512A
1
24V
10
Relay-OFF
11
17
COPYRIGHT© 2001 CANON INC.
Voltage according to the
reading of the main thermistor
Voltage according to the
reading of the sub thermistor
Upper fixing roller
Sub heater
AC
driver
SH-ON
SHDTC
ZEROCROSS
0V
When '0', the AC relay is cut off.
2000 2000 2000 2000
CHAPTER 2 NEW FUNCTIONS
Main thermistor
Thermal switch
Turns off the AC
line at 228˚C.
When the sub heater is powered, '0'.
Relay PCB
F02-907-01
CANON iR8500/7200 REV.1 AUG. 2001
Sub thermistor
RLY
Relay
Front cover
2-153