Lexmark 1020 Color Jetprinter Service Manual - Page 16

4078-00X Service Checks Carrier Transport Service Check FRU Action 1 System Board Check the motor for binds, or loose motor pulley. Turn the printer off and disconnect CN4 from the system board. Turn the printer on and check for a pulse of (approximately) 10 V dc between CN4-1 and ground and CN4-4 and ground, on the system board, as the machine goes through P-O-S-T. If the voltage is not present, check for motor pins shorted to the motor housing. If you find a pin shorted to the housing, replace the motor. If the failure remains, replace the system board. 2 Carrier Transport Motor A noisy or chattering motor or a motor that fails to turn can be caused by: • An open or short in the motor. • An open or short in the motor driver on the system board. • A bind in the carrier transport mechanism. With the carrier transport motor cable disconnected from the system board, check for zero to ten (0 - 10) ohms between the following pins on the motor: CN4-1 and CN4-2 CN4-3 and CN4-4 If the readings are incorrect, replace the motor. 3 Carrier Guide Rod Clean the carrier rod. Note: Do not lubricate the rod or the carrier rod bearing surface. 4 Carrier Transport Belt Idler Pulley Parts Carrier Frame Check for worn, loose or broken parts. Check for obstructions blocking carrier movement. Carrier to carrier frame engagement should be lubricated with grease P/N 1329301. 2-6