Lexmark P122 Photo Jetprinter Service Manual - Page 25

4102-P01 Parts / FRUs Action 2 Paper Feed Motor A noisy or chattering motor or a motor that fails to Engine Frame turn, can be caused by: Assembly System Board • An open or short in the motor • An open or short in the motor driver on the system board • A bind in the paper feed mechanism Check for motor pins shorted to the motor housing. If you find a shorted pin, replace the engine frame assembly. 3 Gears 4 Paper Path With the paper feed motor cable disconnected from the system board, check for approximately 8.4 ohms between pin 3 and 4 on the motor cable. If correct, plug in the printer and check the voltage reading of approximately +17 V dc pulse on pin J3F-4 as the paper feed motor is running. If the voltage reading is incorrect, replace the system board. 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. Check for binds in the gear train and paper feed mechanism by rotating the large feed roll by hand. If you notice a bind, isolate it by removing one of the small idler gears on the inside of the left side frame. If any worn or binding gears or rollers are found, replace the engine frame assembly. Perform the "Paper Path Service Check" on page 2-10, starting at Step 1. Diagnostic Information 2-9