Toshiba e-STUDIO 550, Service Manual

Page: 213 / 346

JUNE 2002 © TOSHIBA TEC 14 - 7 e-STUDIO550/650/810 FUSER UNIT
14. 4. 4. IH control circuit abnormalities
The IH output is stopped when an abnomlity occurs in the IH control circuit.
(1) When the power voltage of the copier is too high or too low
IH output is stopped to protect the IGBT when the input voltage, which is higher or lower than specified
range, is applied to the copier. This is an error [C47].
(2) When the AC is not applied to the IH control circuit
The error that the AC is not applied to the IH control circuit properly is [C47]. The same error occurs
when the thermostat is either activated or blown.
(3) When the temperature of the IGBT is too high
Normally, the IGBT is forcibly cooled down as it becomes hot while the power is supplied to the IH
control circuit. The error [C48] is occurred when this cooling operation is not sufficient and the IGBT
becomes too hot.
(4) When the temperature detection sensor of the IH control circuit is malfunctioning
The error [C49] occurs when the temperature detection sensor is malfunctioning or the IH coil is not
connected properly.
(5) When the ON/OFF of IH coil becomes out of control
When an abnormality occurs at the IH control circuit and the ON/OFF of the IH coil becomes out of
control, CPU decides the error code and counter value of the fuser roller thermistor error status after
detecting the abnormal temperature at the thermistor.
* Abnormal temperature Center thermistor : 230°C
Side thermistor (rear) : 240°C
Side thermistor (front): 270°C