My photocopier (Canon iR1600) displays a message that the output tray is full when i try to photocopy

SOURCE: one side light copy

Your developing unit needs changing and well as your transfer roller.

SOURCE: how to photocopy double sided A4 sheets?

Hi,

you copy first side normaly. then on left side open bypass deck.Put the paper, so that the side on wich you want to print is down. Automatically when you put paper in bypass, the machine ask you wich format is it ( eg. A4 ), confirm with OK, then you need to tell machine wich type of paper ( eg. plain paper ) and OK. then green copy key.