Lexmark 5021-0XX - Manual (Page 286)

4-56 Service Manual
5021-0XX
5. Remove four screws (B) from engine controller board; remove
engine controller board.
Note: When reinstalling flat cables, ensure blue side of cable is
opposite pins on connectors HVCN, I1CN, and I2CN. Flat cable pins
are exposed on only one side (opposite blue side) and must make
contact with metal pins on connectors.
B