E4: Fuser Heater Error - Mita DP-2800 Service Manual

E4: Fuser heater error

Meaning
The fuser heater does
not turn on. [E4 is indi-
cated immediately
after power is on.]
The fuser heater does
not turn on. [E4 is indi-
cated several minutes
after power is on.]
E4 shown
within 30 seconds since
power is on?
Measure resistance
between pins 4 and 5 of
KP-550/YC1.
Less than 1M Ω?
Replace KP-544. If not
recovered, replace cable
between KP-544 and
fuser unit.
Suggested causes
• Connection error between the
engine board and the fuser unit
• Defective engine gate array U2
• Defective comparators on the
engine board
• Defective thermistor (cut)
• Connection error between the fuser
board and the thermistor
• Connection error between the
engine board and the low-voltage
power supply
• Defective engine gate array U2
• Defective transistors, logic gate ICs,
comparators, etc. on the engine
board
• Defective thermistor (showing high
resistance even at heating)
E4
No
Yes
No
Yes
Replace KP-544.
If not recovered,
replace fuser unit.
Replace fuser unit
(req. Temperature
adjustment).
Corrective action
Replace KP-544. Re-
place fuser (temp.
adjustment is required.)
Check/replace S02054
cable.
5A2
6-27