Lexmark T522 Service Manual - Page 70

4520-xxx Cover Open Switch/Cable Service Check FRU 1 Toner Cartridge 2 Cover Open Switch/Cable Assembly Action Check the toner cartridge to make sure it is correctly installed and that the right and left cartridge tracks are not loose or broken. Check to make sure the cover open switch activation tab on the toner cartridge is not broken and that the tab correctly activates the cover open switch spring. Check the cover open switch for proper mechanical operation. If incorrect, repair as necessary. Disconnect the cover open switch cable from J4 at the engine board and measure the voltage at J4-3. It measures approximately +5 V dc. If the voltage is incorrect, replace the engine board. If the voltage is correct, check the voltage at J4-1. If the voltage measures greater than +1.0 V dc, replace the engine board. If the voltage is correct, check the continuity between J4-1 and J4-3 on the cable. If no change in continuity occurs as the switch is activated, replace the cover open switch/cable assembly. If the continuity changes as the switch is activated, replace the engine board. 2-42 Service Manual