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4Fusing unit error (ERROR 71) (ERROR 72) (ERROR 73)
•Turn the power off, then back on.
•Does the fusing unit error occur immediately?
• Yes | Is the thermistor open or shorted? |
| Measure the resistance between |
| thermistor contacts (about 220kΩ at |
| room temperature) (see Fig. |
| see 7.3). |
• Yes Replace the fusing unit.
Heater contacts
Themistor contacts
Figure
▼
• No | Do the thermistor contacts touch the contact assembly properly when the | |
|
| fusing unit is mounted in the printer (see Fig. |
| • No | Adjust the contact. |
▼ |
| Replace the Main Control PCB or power supply board. |
• Yes | ||
▼ |
|
|
• No | Does the fusing unit error occur about 60 seconds after the power is turned on? | |
• No | Check the thermistor for poor contact or replace the Main Control PCB. | |
▼ | Turn the power off, then back on. | |
• Yes | ||
• Is the heater of the fusing unit turned on (when the heater is turned on, light is emitted)? | ||
• Yes | Check thermistor contacts or replace the Main Control PCB or the fuser unit. | |
▼ |
|
|
• No | Is the heater or the thermostat open? | |
| Measure the resistance between the heater contacts (normal resistance: about 0Ω) | |
| (see Fig. | |
• Yes | Replace the fusing unit. | |
▼ |
|
|
• No | Is the AC voltage being supplied to the contacts for the heater of the contact assembly? | |
| (Refer Fig. | |
| • No | Replace the Main Control PCB or the power supply board. |
▼ | Check the heat contact of the fusing unit and the contact assembly for poor contact | |
• Yes |
(see Fig.
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