To replace the main processor board:1. Remove front panel.2. Place the front panel with the user interface face down and remove the six screws from the metallic screen,as shown in the figure below. Remove the metal plate.3. Remove the two screws either side of the rear of the battery compartment recess. These are the screwsthat hold the main processor board in position.4. Carefully disconnect the ribbon cable. Take care as this could easily be damaged by excessive twisting.5. Replace the main processor board6. Reassemble the front panel using the reverse procedure. Make sure the ribbon cable is reconnected to themain processor board and that all eight screws are refitted.7. Refit the front panel.8. Refit and close the access covers then press the hinge assistance T-pieces so they click back into the frontpanel moulding.9. Once the unit has been reassembled, carry out the standard commissioning procedure as defined in theCommissioning chapter.Note:After replacing the main processor board, all the settings required for the application need to be re-entered. This may be doneeither manually or by downloading a settings file.V01601Figure 303: Front panel assembly2.5.2 REPLACEMENT OF COMMUNICATIONS BOARDSMost products will have at least one communications board of some sort fitted. There are several different boardsavailable offering various functionality, depending on the application. Some products may even be fitted twoboards of different types.To replace a faulty communications board:1. Remove front panel.2. Disconnect all connections at the rear.3. The board is secured in the relay case by two screws, one at the top and another at the bottom. Removethese screws carefully as they are not captive in the rear panel.4. Gently pull the communications board forward and out of the case.5. Before fitting the replacement PCB check that the number on the round label next to the front edge of thePCB matches the slot number into which it will be fitted. If the slot number is missing or incorrect, write thecorrect slot number on the label.Chapter 25 - Maintenance and Troubleshooting P446SV670 P446SV-TM-EN-1
