Lexmark C750 Service Manual - Page 89

5060-00x 135 Error code Hot fuser The fuser assembly is running over temperature or the backup roll fuser lamp has been on too long. Error 135 may also indicate a problem in the fuser assembly with the backup roll fuser bearings, back up roll thermistor, LVPS, or engine board. Step 1 Action and questions Turn the printer on, open the right side fuser access door and observe the backup roll lamp to see if it turns on and off. You may have to observe the lamp for a few minutes to see if it turns on and off. Does the lamp turn on and off. 2 Turn the printer on. Measure the voltage on engine board connector J10-12. The voltage should be approximately +0.13 V dc to +0.64 V dc as the backup roll turns on and off. Does the voltage change? Replace the fuser assembly. See "Fuser assembly removal" on page 4-31. Yes Go to step 2 No Replace the LVPS assembly. See "Low voltage power supply (LVPS) removal" on page 4-38. Replace the engine board assembly. See "Engine board removal" on page 4-29. Diagnostic information 2-55