Ricoh M281 Series Service Manual page 195

4. REPLACEMENT AND ADJUSTMENT
4.1 NOTES ON THE MAIN POWER SWITCH
4.1.1 PUSH SWITCH
The main power button of this machine has been changed to a push-button switch (push button)
from the conventional rocker switch. The push switch has characteristics and specifications
different from the rocker switch. Care must be taken when replacing and adjusting parts.
Characteristics of the Push Switch (DC Switch)
Power is supplied to the machine even when the main power is turned OFF.
The push switch in this machine uses DC (direct current). Therefore, if the AC power cord is
connected to an electrical outlet, power is supplied to the controller board, the operation unit
and other modules even when the main power is turned OFF. When replacing electrical
components in this stage, it can damage other electrical components.
So, when performing maintenance work such as replacing parts, in addition to turning OFF
the main power with the push switch, always unplug the AC power cord after the main power
LED on the operation panel is turned OFF.

If you unplug the power cord before turning OFF the main power LED, some icons on
the operation panel will not appear at the next start-up. Restarting the machine again
will solve this issue.
When you disconnect the power cord from the AC wall outlet, inside the machine there is
still residual charge.
When you disconnect the power cord from the AC wall outlet, there is still residual charge
inside the machine for a while. Therefore, if you remove boards in this state, it can cause a
blown fuse or memory failure.

How to remove the residual charge inside the machine
After you unplug the power cord from the AC wall outlet, in order to remove the residual
charge from inside the machine, press the main power switch. The charge remaining in
the machine is released, and it is possible to remove boards.
When you reconnect the AC power cord into an AC wall outlet, the machine will start
automatically.
In order to remove the residual charge, push the main power switch after you disconnect the
AC power cord. At that time, the power ON flag inside the machine is set. Therefore, after you
finish work on the machine and reconnect the power cord to the AC, even if you do not press
the main power switch, the machine will start automatically and the moving parts will begin to
move. When working on moving parts, be careful that fingers or clothes do not get caught.
SM
Notes on the Main Power Switch
4-1 D255/D256/M281/M282