2NC/2NF/2NG/2NN/3P7/3P8/3P9
1-4-28
6000 Broken fuser heater wire 
(main)
When the fuser thermistor 1 
reaches primary stable tem-
perature after a warm-up start 
and the fuser thermistor 2 is 
less than 90 ° C/194 °F.
Fuser unit 1. Check that no paper jam is present.
2. Confirm that the wiring connector is 
firmly connected and, if necessary, 
connect the connector all the way in.
Fuser unit and mmain/engine PWB 
(YC14)
3. If the wiring is disconnected, shorted or 
grounded, replace the wiring.
4. Replace the Fuser unit and execute 
U167 counter clear (see page 1-3-56).
(Deteriorated sensitivity due to the toner 
adhered to the center thermistor.)
Main/Engine PWB 1. Check the main/engine software and 
upgrade to the latest, if necessary.
2. Replace the main/engine PWB (see 
page 2-2-11).
Power source 
PWB
1. Confirm that the wiring connector is 
firmly connected and, if necessary, 
connect the connector all the way in.
Power source PWB (YC4) and main/
engine PWB (YC14)
2. Replace the power source PWB (see 
page 2-2-27).
Fuser heater 1. Replace the Fuser unit and execute 
U167 counter clear (see page 1-3-56).
6020 Abnormally high fuser 
thermistor 2 temperature 
(Center)
Fuser thermistor 2 detects a 
temperature higher than 
210°C/410°F.
Fuser unit 1. Confirm that the wiring connector is 
firmly connected and, if necessary, 
connect the connector all the way in.
Fuser unit and main/engine PWB 
(YC14)
2. If the wiring is disconnected, shorted or 
grounded, replace the wiring.
3. Replace the Fuser unit (see page 1-5-
48).
Main/Engine PWB 1. Check the main/engine software and 
upgrade to the latest, if necessary.
2. Replace the main/engine PWB (see 
page 2-2-11).
Code Contents Related parts
Check procedures/
corrective measures