Fault Code 059-315: WC-5325, 5330, 5335

059-315 – Center Thermistor Overtemperature

This fault needs to be cleared from diagnostics by resetting NVM Read / Write code 744-005 back to “0” (it will show a 1,2, 3, or 4 if the machine is in a fuser error state) … Then the machine will attempt to warm up again.

Check the connections where the fuser sits into the machine for oxidation or damage or bent pins, etc.

You can also check the thermistor with an Ohm meter… the Center Thermistor can be measured at pins 1 and 5 on the fuser’s main connector (JC621). It should measure 3k ohms or higher (the resistance there increases as the temperature increases… if it measures infinite resistance then something is wrong with the wiring or the thermistor itself).  

the thermistor itself is not spared so unless you have another fuser with a good used thermistor, or can find and repair the cause of the problem (for example a broken wire or pinched wire),  you will probably have little choice but to buy a new Fuser Assembly (5325FA).