November 2003 © TOSHIBA TEC 5 - 47 e-STUDIO3511/4511 TROUBLESHOOTING
5.1.11 Fuser unit related service call
Be sure to turn OFF the power and unplug the power cable beforehand when checking the IH control
circuit and IH coil.
The fuser unit itself or the part of the unit remains heated and the capacitors are still charged after a
while the power cable is unplugged. So make sure the unit is cooled down enough before checking.
[C410] Thermistor or heater abnormality at power ON
1. Check the thermistors
(1) Check if the connectors are disconnected.
(2) Check if the main, sub and front edge thermistors are in contact with the surface of the fuser belt
properly?
(3) Check if the harnesses of the main, sub and front edge thermistors are open circuited.
2. Check the IH control board and IH coil
(1) Check if the IH coil is broken.
(2) Check if the connector of the IH coil is disconnected.
(3) Check if the thermostats are blown.
(4) Check if the connectors on the IH control board are disconnected (AC input connectors CN450,
451 and LGC I/F connectors CN455, 456).
(5) Check if the IH control board or the switching power supply unit is abnormal.
3. Check the LGC board
(1) Check if the connector CN358 is disconnected.
(2) Check if the conductor pattern on the LGC board is short circuited or open circuited.
(3) Replace the LGC board.
4. Clear the status counter
After repairing the matter which caused the error [C410], perform the following:
(1) Turn ON the power while [0] and [8] are pressed simultaneously.
(2) Key in “400”, then press the [START] button.
(3) Change the current status counter value “1” or “2” to “0”, then press the [ENTER] button or
[INTERRUPT] button (to cancel [C410]).
(4) Turn the power OFF and then back ON. Make sure that the equipment enters the normal ready state.
[C430] Thermistor abnormality after abnormality judgment
[C440] Heater abnormality after abnormality judgment
1.2.3. Check the thermistors, IH control board, IH coil and LGC board
Check the above components following the procedure 1, 2 and 3 for [C410].
4. Clear the status counter
Change the current status counter value (08-400) “4” to “0” for [C430] and “5”, “7” or “9” to “0” for
[C440], taking the same procedure as that for [C410].
* The status counter value is as follows in the following cases. Change them to "0" respectively.
• The error occurred during warming-up : "4" or "5"
• The error occurred after the equipment has become ready: "7"
• The temperature detected by the main thermistor is 230°C or higher: "9"
• The temperature detected by the sub thermistor is 230°C or higher: "9"
CAUTION:
CAUTION: