ir c5051 duplex copy quality second side

[pontiac]

When using duplex function first side is normal second side is light. Copy quality is the same weather using adf or placing on glass. We swapped out transfer belt ,drums and developer units for testing no change. Thanks

[Phil B.]

When using duplex function first side is normal second side is light. Copy quality is the same weather using adf or placing on glass. We swapped out transfer belt ,drums and developer units for testing no change. Thanks

what is the 2nd side Transfer bias set at?