Lexmark T620 Service Manual - Page 110

4069-5XX/7XX Paper size switch not selecting paper size that is selected. FRU 1 Paper Size Switch High Capacity Feeder Option Control Board Action Check for continuity between the common pin (J5-1) and the pin of the paper size selected. J5-1 (Black): Common Lead J5-2 (Blue) B5 J5-3 (Green) Executive J5-4 (Yellow) A4 J5-5 (Orange) Letter J5-6 (Red) Legal J5-7 (Brown) A5 If any position does not measure continuity when selected, replace the paper size switch assembly. If the switch assembly is operating correctly, replace the high capacity feeder option control board. 24X Paper Jam Check Tray X Message displays when Tray X is empty. No Tray X Message displays. FRU 1 High Capacity Feeder Option Control Board 2 Elevator Top Optical Sensor Cable Elevator Top Optical Sensor Action Check the voltages on the board at J4-1(red) and J4-3 (blue). The voltages measure approximately +5 V dc. If incorrect, disconnect J4 from the board and measure the voltages again. If incorrect, replace the high capacity feeder option control board. Check the continuity of the sensor cable. If incorrect, replace the cable. If correct, replace the top optical sensor assembly. 2-82 Service Manual