This is a fuser thermistor, it is very common to see in a fuser unit. Its main function is to determine when to turn on and turn off the heater lamp that maintains the operating temperature of the fuser unit. So, what is thermistor?
Thermistor – is a resistance thermometer, or a resistor whose resistance is dependent on temperature. The term is a combination of “thermal” and “resistor”. It is made of metallic oxides, pressed into a bead, disk, or cylindrical shape and then encapsulated with an impermeable material such as epoxy or glass.
The very common errors that the Toshiba MFD if the fuser is malfunction is C447. let’s see what error C447 and how does it relates to the thermistor?
Error C447 – Fuser unit related service call. While in the READY state, one of the thermistors detected the specified temperature or higher; Heater lamp abnormality after abnormality judgment (temperature abnormality at ready status)
By Service mode being performed by a service personnel this error can be cleared or reset but in a couple of prints the error comes back this means something is wrong.
To solved this error one solution is by replacing the thermistor, because after resetting, the machine is still capable to print but in a matter of hours the error C447 comes back then this means that the heater lamp is good and the only remaining parts that needs to isolate is the thermistor. Once done replacing the Toshiba MFD is now back to normal condition.