Lexmark 3000 Color Jetprinter Service Manual - Page 20

Paper Feed Service Check If your machine does not have paper jam problems, continue with the service check. If your machine does have a paper jam problem, examine it for the following before you begin the service check: • Check the entire paper path for obstructions. • Be sure there is not too much paper in the sheet feeder. • Be sure the correct type of paper is being used. • Check for static in the paper. FRU Action 1 System Board Unplug the printer and disconnect CN3 from the system board. Plug the printer in and check for a pulse of 24 V dc between CN3-1 and ground and CN3-2 and ground on the system board. If the voltage is not present, check for motor pins shorted to the motor housing. If you find a shorted pin, replace the motor. If you still have a failure after replacing the motor, replace the system board. 2 Paper Feed 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, or a bind in the paper feed mechanism. With the paper feed motor cable disconnected from the system board, check for 60 ohms (±15 ohms) between the following pins on the motor: Pin 2 to Pin 5, Pin 2 to Pin 6 130 ohms (±20 ohms) between pins 5 and 6. If the readings are incorrect, replace the motor. Although the paper feeds in a forward direction only, the paper feed motor turns in two directions. If the paper feed motor turns in one direction only, replace the system board. Binds in the paper feed motor or gear train can cause intermittent false paper jam errors. Remove the paper feed motor and check the shaft for binds. Also check for loose or worn motor gear. 2-8