Minolta Di450 Service Manual page 457

C0500, C0510
Step
1 Upper Fusing Roller Heater Lamp turns ON
when the Power Switch is turned ON.
2 Lower Fusing Roller Heater Lamp turns ON
when the malfunction is reset with the surface
temperature of Lower Fusing Roller Heater
Lamp is 140°C or less as indicated on "Level
History" under the Tech. Rep. mode.
3 Upper and Lower Fusing Roller Thermistors
are installed properly.
4 Upper and Lower Fusing Roller Thermistors
are dirty.
5 Upper Fusing Roller Thermistor operation: the
resistance across CN217-2 and 3 on the Fus-
ing Unit end is infinity with CN217 (4P) discon-
nected.
6 Lower Fusing Roller Thermistor operation: the
resistance across CN218-2 and 3 on the Fus-
ing Unit end is infinity with CN218 (4P) discon-
nected.
7 Upper Fusing Roller Thermostat and Upper
Fusing Roller Heater Lamp continuity: there is
continuity across CN11-1 and 8 with CN11
(16P) disconnected.
8 Lower Fusing Roller Heater Lamp continuity:
there is continuity across CN11-9 and 16 with
CN11 (16P) disconnected.
Check
T-49
Result Action
YES Correct thermistor for
mounting position and/or
clean.
NO Check step 7 and onward.
NO Reinstall.
NO Clean.
YES Change Upper Fusing
Roller Thermistor.
YES Change Lower Fusing
Roller Thermistor.
NO Change thermostat and
heater lamp.
NO Change heater lamp.