2. Label and remove any wires connected to the terminal block at the top of the switcher card. Include as part of the label the name of the
terminal block and the specific terminal the wire connects to. You will need to reattach these wires to the new switcher card.
3. Remove the #6 Torx screws at each corner of the switcher card. These screws are fastened to metal standoffs secured to the back of the bay.
Leave the standoffs fastened to the back of the bay. You will remount the new switcher card to them.
4. Disconnect the CPU switcher card’s J1 header connector from the P1 header connector on the adjacent 24-point I/O card.
Install the New CPU Switcher Card
1. Place the new switcher card in the same location where you removed the old one and connect its J1 header connector to the P1 header
connector on the 24-point I/O card.
2. Fasten the switcher card to the metal standoffs at each corner of the card using the four #6 5/16” Torx screws provided with the service kit.
3. Reattach the two labeled connectors and any other wires you removed from the old switcher card to the appropriate locations on the new
switcher card.
Reinstall the CPU Motherboard
1. Attach the CPU motherboard’s J1 connector to the newly installed CPU switcher card’s P1 connector.
2. Fasten the CPU motherboard to the standoffs extending from the rear of the CPU bay using the six #6 5/16 inch Torx screws you removed
from the board earlier (see Figure 3 for screw-hole locations).
3. Reconnect the labeled cables and wires to the appropriate locations on the new CPU motherboard. Refer to Figure 2 for the location of each
labeled connection.
4. Reinsert the CPU daughter card in the right-most slot of the CPU motherboard (refer to Figure 1 for the correct location).
5. Reconnect the cables labeled “service port” and “front display” to the appropriate locations on the CPU daughter card. The service port cable
is the thinner of the two cables.
6. If you are also replacing the class B motherboard, skip ahead to
Replacing the Class B Motherboard
otherwise follow the instructions in the
subsection below to complete the replacement of the CPU switcher card.
Prepare System for Operation
Complete the replacement procedure using the instructions below.
1. Close the door to the primary CPU bay.
2. Reapply system power at the breaker.
3. Restore battery power to the cabinet by reconnecting the battery cable at the PDM.
4. Redress and close the main cabinet door.
The system is now ready for normal operation.
Replacing the Class B Motherboard
Introduction
The class B motherboard is located in the Secondary CPU bay. The motherboard houses the secondary CPU card and mounts to the far left of the
Secondary CPU bay (see Figure 4).
Note:
Actually, a full-length motherboard cannot be mounted in the left-most slot of an expansion bay; that slot must remain empty so that the wires
connected to the PDI are easily accessible. The class B motherboard is, however, the card mounted furthest to the left in the bay. Refer to Figure 4 for
the location of the board.
Removing the class B motherboard involves removing all wiring attached to the board, uninstalling the CPU daughter card mounted to the board, and
unscrewing the four Torx screws that fasten the board to standoffs at the rear of the bay.
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579-272 Rev. C
CPU Switcher Card and Class B Motherboard Replacement Instructions
