Lexmark T520 Service Manual - Page 85

4520-xxx FRU 2 Fuser Lamp Fuser Top Cover Assembly 3 LVPS LVPS to Fuser AC Cable 4 Fuser Top Cover Assembly (Thermal Fuse/Thermistor Assembly) Action Remove the controller board. Run the Diagnostic Print Test and observe the lamp through the left side frame. If the lamp does not come on, do the following: • Remove the redrive assembly. • Remove the fuser assembly, disconnect the LVPS to fuser AC cable from the fuser assembly and remove the fuser. • Verify that the lamp is installed correctly. If correct, check the continuity of the fuser top cover assembly by verifying the lamp contacts on the right contact assembly. If incorrect, check continuity of the fuser lamp. If incorrect replace the lamp. If correct replace the fuser top cover assembly. Caution: When taking measurements for AC power, observe all safety precautions. Measure the AC line voltage between the two connectors on the fuser end of the LVPS to fuser AC cable. If the voltage is incorrect, turn the power off, and remove the LVPS. Measure the AC line voltage between pins CN1-1 and CN1-3 on the board. If correct, check the continuity of the LVPS to fuser AC cable. If incorrect, replace the cable. If the AC line voltage at CN1 is incorrect, check fuse F2. If the fuse is blown, replace the fuse. If the fuse is not blown, replace the LVPS assembly. Disconnect the thermistor cable from the fuser board at J2. Resistance: • HOT J2-1 - J2-2 = 2.5K ohms • COLD 150K ohms to 260K ohms Diagnostic Information 2-57