Minolta Di 620 Manual page 271

C0500, C0510
Step
1 Remove the Fusing Unit Front Cover and
then turn ON the Power Switch. Does H1
turn ON at this time?
2 Does H2 turn ON when the malfunction is
reset with the surface temperature of the
Lower Fusing Roller at 135°C as indicated
on "Level History" available from the Tech.
Rep. mode?
3 Is TH1 or TH2 installed properly?
4 Is TH1 or TH2 dirty?
5 Measure the resistance of TH1 (across
CN28-2 and 3 on the Fusing Unit end). Is
the measurement infinity?
6 Measure the resistance of TH2 (across
CN32-2 and 3 on the Fusing Unit end). Is
the measurement infinity?
7 Does the voltage across PJ8A-3B on PWB-
A and GND change from DC5V to DC0V
when the Power Switch is turned ON?
8 Does the voltage across PJ8A-4B on PWB-
A and GND change from DC5V to DC0V
when step 2 is performed again?
9 Unplug CN4 (8P). Is there continuity
across CN4-1 and 4 on the Fusing Unit
end?
10 Unplug CN4 (8P). Is there continuity
across CN4-5 and 8 on the Fusing Unit
end?
11 Is the voltage across PJ4C-3A on PWB-C
and GND, and across PJ4C-2A on PWB-C
and GND, DC5V?
Check Item Result
NO Check step 7 and onward.
NO Check step 8 and onward.
NO Correct the installation of TH1 or TH2.
YES Clean or change TH1 or TH2.
YES Change TH1.
YES Change TH2.
NO Change PWB-A.
NO Change PWB-A.
NO Check H1 or TF1 for continuity.
NO Check H2 or TF2 for continuity.
YES Change PWB-A, SSR1 or SSR2.
NO Cange PWB-C.
T-56
Action