Lexmark T620 Service Manual - Page 151

4069-5XX/7XX FRU 3 Toner Sensor Action The toner sensor cable is part of the front harness and part of connector J25 on the system board. Check the voltage at J25-11. It reads approximately +5 V dc. If incorrect, replace the system board. If correct, check the voltage at J10-12. It reads approximately +5 V dc with the system board removed from the printer. If incorrect, replace the system board. If correct, replace the toner sensor assembly. A bad ground connection between J25-14 on the system board and pin 3 on the toner sensor results in a 929 service error. Transfer Roll Service Check Service Tip: The transfer roll is 51.02 mm (2.009 inch) circumference. Any print quality problems such as lines that are spaced 51.02 mm apart indicate you should check the transfer roll for damage, toner or foreign material buildup. Service Tip: The transfer roll assembly is part of the Maintenance Kit and is replaced when a '80 Scheduled Maintenance" message displays. Ask the customer if they have replaced the transfer roll recently. CAUTION: Make sure the printer is powered Off before making any checks on the transfer roll or associated parts for personal safety and to prevent damage to the printer. FRU 1 Transfer Roll Assembly Action Check the transfer roll for any signs of toner buildup, surface damage to the roll, oil or other contaminants on the surface of the roll. Replace the transfer roll as necessary. Diagnostic Information 2-123