M126/M127/M128  6-86  SM 
6.5.19  840.XX SERVICE CHECK 
 
Step  Questions / actions  Yes  No 
1 
POR the machine into configuration 
mode. Go to the disable scanner 
menu item. See “Disable Scanner” 
in “System Maintenance”. Touch 
“Enable ADF/FB -Enabled" and 
press "Submit" to save the change. 
POR the machine to operating 
mode. Try running a copy from the 
ADF and flatbed. 
Did the 840.xx error recur? 
Go to step 2. 
Stop. Problem 
resolved. 
2 
Re-enter Configuration mode, scroll 
to and select the Disable Scanner 
menu item. 
Does the screen display "ADF 
Disabled" or "Auto Disabled"? 
Go to step 3.  Go to step 8. 
3 
Check the ADF cable connections 
on the ADF relay card and connector 
J17 on the controller board. Also 
inspect the cable connections on 
J28, J12, 13 and J30 on the 
controller board. 
Are the connections properly 
connected? 
Go to step 5.  Go to step 4.