Protective Functions; Error Detection - Canon imageRUNNER 7095 Service Manual

Chapter 9

9.4 Protective Functions

9.4.1 Error Detection

The machine checks for the following types of errors in relation to its fixing temperature control mecha-
nism:
[1] temperature control error by main thermistor (tH1)
[2] sensor error by sub thermistor (TH2)
[3] current shut-down in response to overheating by thermal switch (TP1)
ERROR CODE:
E000 (heating failure)
0000 After the power is turned on, the reading of the main thermistor fails to reach 70 deg C or more within
3.5 min.
E001 (overheating)
0001 The reading of the main or sub thermistor is 230 deg C or more for 2 sec (detection by hardware).
0002 The reading of the main or sub thermistor is 230 deg C or more for 2 sec (detection by software).
0003 The difference between the readings of the main thermistor and the sub thermistor is 50 deg C for 1
sec or more (main > sub).
0004 The difference between the readings of the main and the sub thermistor is 50 deg C for 1 sec or more
(main >/= sub ).
9-10
Voltage suited to
J508B
reading of main thermistor
1
M-TEMP
7
0V
8
S-TEMP
9
0V
10
Fixing upper roller
20
Main
heater
J505A
1
Sub heater
M-H-DTC
9
M-H-ON
10
0V
11
S-H-ON
12
AC driver
S-H-DTC
13
ZEROCROSS
14
0V
15
100V/200V
16
When '1', main heater goes on
J505A
1 1
When '0', AC relay goes off
24V
10
Relay OFF*
11
16
Voltage suited to
reading of sub thermistor
Main thermistor
Thermal switch
At 228 deg C,
cuts off AC line
RLY
Relay
When sub heater is
supplied with power, '0'
Relay PCB
F-9-13
Sub thermistor
Front cover
0010-8239