When carrying out maintenance work on the device, proceed as follows:

1. Remove all mobile data carriers (USB sticks, memory cards and so on).

2. Shut down the device.

3. Switch off the device.

4. Unplug the mains cable from the socket.

5. Remove the housing cover.

6. Carry out the maintenance work.

7. Attach the housing cover again.

8. Put the device into operation again.