Lexmark E330 Service Manual - Page 75

4505 Service checks Service checks which involve measuring voltages on the LVPS/HVPS (low voltage power supply/high voltage power supply board) should be performed with the printer positioned on its back side. Note: When you make voltage readings, always use frame ground unless another ground is specified. See "Wiring diagram" on page 5-4 for more information. Cold fuser service check Make sure the correct voltage lamp is installed. The voltage rating is stamped on one of the lamp contacts. FRU Fuser AC cables LVPS/HVPS Fuser Action If the fuser lamp comes on and a fuser failure light error code displays, be sure the thermistor is contacting the hot roll and the thermistor cable is firmly seated in connector J15 on the controller card. Check for excessive toner buildup on the surface of the thermistor. Clean as necessary. With the printer unplugged, disconnect the thermistor cable from J15 on the controller card. Measure the resistance of the thermistor. The resistance measures from approximately 1K ohms immediately after printing or POR to approximately 240K ohms when thermistor reaches room temperature. (It may take 30 minutes to cool.) Replace the fuser assembly as necessary. Diagnostic information 2-47