• NEVER touch the areas outlined in red in the photos below, to prevent electric shock caused by residual charge.
  • A residual charge of about 100V-400V remains in the AC circuits on the PSU board for several months even when the board has been removed from the machine after turning off the machine power and unplugging the power cord.
  • The procedure to discharge residual charge from the machine by unplugging the power cord from the AC wall outlet and pressing the main power switch works only for the DC circuits on this board. Residual charge remains in the AC circuits.

  1. Remove the left cover. (Left Cover)
  2. Remove the bracket [A].
  3. Remove the PSU cooling fan (for MP 4055 SP/5055 SP/6055 SP only). (PSU Cooling Fan (MP 4055 SP/5055 SP/6055 SP Only))
  4. Remove the PSU [A].