1. Remove the optional paper feed unit from the main machine.
  2. If the optional paper feed unit is installed on the caster table, remove it from the caster table.
  3. Remove the paper feed tray [A] of the optional paper feed unit by pulling it out.
  4. Turn over the optional paper feed unit [A], and then remove the board cover [B]. (hook×2)
  5. Remove the mainboard [A]. (hook×3)