Code :

Code: E850-
Description: There is a fault in the double-feeding detection unit.
The double-feeding sensor (reception) fails to attain an ultrasonic signal of a specific level.
Remedy: Remove paper lint form the surface of the double-feeding sensor (reception). Remount the double-feeding sensor (transmission, reception). Disconnect and then connect J509 and J550 of the DC controller PCB. Replace the double-feeding sensor (transmission, reception). Replace the double-feeding sensor PCB (transmission, reception).