M126/M127/M128 6-56 SM
6.5.5 COVER INTERLOCK SWITCH SERVICE CHECK
Make sure a print cartridge assembly is installed and the cover closes all the way,
engaging the cover open switch lever.
FRU Action
Cover interlock switch
Disconnect the cover interlock cable from the controller
board at J11.
With the machine turned off:
1. Verify continuity between cable pin 1 and pin 2 with the
door closed and discontinuity with the door open.
2. Verify continuity between cable pin 1 and pin 3 with the
door open and discontinuity with the door closed.
3. Verify discontinuity between cable pins 2 and 3
whether the door is open or closed.
If any fail, then replace the cover interlock switch.
If both pass continuity, then turn the machine on, and
measure +5 V dc on pin 2 at J11 on the controller
board.
Verify pin 3 at J6 is ground.
If voltage or ground is not present, then see “Engine
Board Service Check” in “Troubleshooting” for more
information.