Lexmark T430 Service Manual - Page 75

4048-1xx Cold fuser service check FRU Fuser assembly LVPS Fuser assembly Action Unplug the printer and disconnect the fuser heater cable from the LVPS card connector (CN3). See "Low voltage power supply (LVPS)" on page 5-7 for more information. Check for continuity across the fuser heater (pins #1 and #3 or outer pins). If there is no continuity, replace the fuser assembly. See "Fuser assembly removal" on page 4-26. If there is continuity, follow these steps: 1. Reconnect the fuser heater cable. 2. Replug and turn the printer on. Measure the voltage between the connectors on the back of the switch. It should match the line voltage. 3. If line voltage is not present, replace the LVPS. Make sure the fuser thermistor is correctly connected to the controller card (J18). If the fuser heater comes on and a fuser failure error code displays, be sure the thermistor is firmly seated in connector J18 on the controller card assembly. (The thermistor cable goes through the frame by way of a connector.) Unplug the printer and disconnect the thermistor cable from the controller card (J18). Measure the resistance of the thermistor. The resistance measures approximately 240K to 400K ohms when cool (approximately 40°C or 104°F) and 1.5K to 3K ohms hot (immediately after running a printout). Replace the fuser assembly as necessary. Hot fuser service check FRU Fuser assembly Action Unplug the printer and measure the resistance of the thermistor. The resistance measures 240K to 400K ohms when cool (approximately 40°C or 104°F) and 1.5K to 3K ohms hot. Replace the fuser assembly as necessary. Diagnostic information 2-41