Warning

Read completely the instructions detailed in Preliminary Service Information.

This chapter details the removal and refitting of the Motherboard, additional processor board and associated Power board. Each one has a separate procedure.

System motherboard

Removing

1. Unplug all external cables and leads from the system back panel connectors (i.e. serial, parallel, video, keyboard, mouse) on the motherboard and from any expansion cards.

Remove the screws which secure the metal plate over the electronics chamber. The screws are along the top and right edges of the plate as shown in the following illustration:

1 Protective Metal Plate 2 Securing Screws

Caution

It is vital that you remember the exact cable and connector arrangement of your hard disks, particularly if you are using a RAID (Redundant Array of Independent Disks) configuration. If you fail to restore the arrangement so that all cables and plugs are as they were originally, you risk losing all the data on your hard disks.

Rotate the right edge of the plate slightly towards you and unhook the left edge. Removing the plate uncovers the motherboard:

1 Support / retaining strut 6 Busbars to Power supply 2 Termination/extra CPU card 7 SMIC card (bottom slot) 3 Aux. power connection 8 SMIC cable to power board 4 Hard Disk SCSI Cable 9 Power board connections 5 Remov. media SCSI cable

Remove six screws from the periphery of the subplate which surrounds the serial, parallel and video connectors on the back panel of the server.

1 Fixing screws 2 system rear panel

Now remove the System Management Interface Card (SMIC). Unplug its ribbon cable, which is attached to the distribution board at the top of the electronics chamber, using the ejector latches fitted to the sockets.

1 Cable retaining latches 2 Ribbon cable socket

6. Remove the termination board, or, if fitted, the metal strut which supports the additional CPU card. There is a single screw on one end of the strut with a hook on the other. Then remove the CPU card.

7. Remove and put in a safe place, any fitted expansion boards.

Caution

All boards and assemblies should be placed on an antistatic surface or within an antistatic container as they are removed from the server.

8. Unplug the DC power connectors. One from the power distribution panel at the top of the electronics chamber, then the other from the lower right hand side (direct from the PSU).

9. Unplug the data ribbon that connects to the power distribution panel. Again, use the ejector latches.

10. Unplug the Floppy Drive connector.

11. Unplug the two SCSI interface cables from the connectors at the bottom of the motherboard.

12. Using an M5 socket, release the five busbar connections at the base of the motherboard.

Now remove 21 screws which secure the board to the centre spine of the server, as shown:

Caution

When refitting the motherboard, due to the very high operating frequencies of modern systems, it is extremely important that all of the mounting screws are refitted to ensure effective grounding to the server metalwork over the whole board area.

Lift the motherboard gently off the support lug at the top right corner in the electronics chamber and place on a suitable antistatic surface.

Ports sub-plate

If the motherboard is being replaced, the metal sub-plate supporting and identifying the rear ports must be removed to be fitted to the new motherboard.

Carefully remove the port fixing bolts and lift the plate clear.

1 Top right corner of m’board 3 Ports sub-plate 2 Ports on motherboard 4 Port mounting bolts

Fitting the Motherboard

1. Replace the six screws which secure the connector sub-plate, on the back panel, to the server chassis.

Attach the motherboard to the centre spine of the server using the 21 screws as shown in the following illustration:

Reconnect the hard disk cable from the drive module to the appropriate connector as it was originally.

Caution

It is vital that you remember the exact cable and connector arrangement of your hard disks, particularly if you are using a RAID (Redundant Array of Independent Disks) configuration. If you fail to restore the arrangement so that all cables and plugs are as they were originally, you risk losing all the data on your hard disks.

5. Plug the Floppy Drive and Front Panel cables into their respective connectors.

6. Plug the DC power cables into their respective connectors on the power distribution board at the top of the electronics chamber. These connectors are keyed and cannot be plugged incorrectly. Do not use force; you may be trying to plug a cable into the wrong connector.

7. Replace the bus termination board or the additional CPU card (plus its support strut).

8. Replace any expansion cards and their appropriate ribbon cables.

Replace the SMIC card in the lowest EISA slot and plug its cable into the power distribution board at the top of the electronics chamber. Ensure the plug is firmly fixed into the socket using the latches.

1 Cable retaining latches 2 Ribbon cable socket

10. Using a torque wrench set to 5 Nm, connect up and tighten the busbar connections at the base of the motherboard.

11. Refit the auxiliary power supply cable to the lower right hand side power connector.

12. Ensure all the processors and memory modules are refitted correctly.

13. Hook the left edge of the protective metal plate in place and secure the plate to the server chassis using the screws along the top and right edges.

14. Reconnect all cables and leads to the back panel port connectors.

Note

You must always refit all protective metal plates. These plates, in addition to providing protection for delicate components, contribute to an effective flow of cool air through the machine.

Motherboard Power Distribution Panel

The motherboard power distribution panel is fixed to the inner roof of the electronics chamber and is positioned at right angles to the motherboard. The following illustration shows the connectors and the eight securing screws on the board:

A Securing Screws (x8)     1 Loudspeaker Connector 6 SMIC Card Connector 2 Motherboard connector 7 Power from motherboard 3 Fan Board Connector 8 Power from motherboard 4 Aux. power connector 9 Power to/from m’board 5 SMC connection 10 3.3 v supply to m’board

Removing

Unplug all connectors on the panel, noting their position.

Note

You may have to remove the termination/additional CPU card to provide enough working space to complete this procedure.

Remove eight securing screws and remove the panel.

Fitting

Fasten the panel to the inner roof of the electronics chamber with the 8 screws.

Plug the various connectors into the board. Each connector is keyed so that it cannot be plugged into the wrong socket.