Maintenance
4-4 SIMATIC Panel PC 670 / 870 Operating Unit, Equipment Manual
Edition 07/01
4.2.2 Panel PC 870
Proceed as follows:
1. Disconnect the power supply.
2. Swing open the mounting panel to obtain access to the rear of the
PC 870.
3. Loosen the four (retained) knurled screws which secure the compu-
ting unit to the rear side of the operating unit (see also Figure 3–3).
4. Swing the computing unit away to the left, whereby the two left clips
act as hinges and thus prevent an unintentional releasing of the
computing unit.
Operating unit Clips acting as hinges
Computing unit
Computing unit,
swung away by 90
Knurled screw
Fig. 4-3 Swinging the computing unit away from the operating unit (viewed from above)
5. Remove the cable connectors K1 and K2 of the operating unit (see
Figure 4-4) from their corresponding counterparts on the computing
unit.
6. Lift the computing unit off the hinges of the operating unit and place it
down carefully.
If necessary, you can now remove the operating unit by loosening
either the screws or, depending on the version, the six clamps which
secure the operating unit to the mounting panel (see Figure 3-3).
Removing the
computing unit