Rear Panel

Power Supply and optional Battery Back Up unit (BBU)

Module Power Output

Removing and fitting power modules

Removing the complete Power Tray

Optional Battery backup unit (BBU)

Battery Isolation (Fireman’s Switch)

System management controller (SMC)

Rear Panel

The rear panel contains the various ports and connectors as shown in the following illustration:

1 Keyboard Connector (PS/2) 2 Mouse Connector (PS/2) 3 Serial Port COM2 4 Serial Port COM1 5 SMC Modem Port 6 Video Connector 7 Parallel Port 8 Expansion Slot Openings 9 Stud for Antistatic Strap 10 Optional Battery back up unit 11 Battery isolation link 12 AC Power Socket 13 Power Supply modules

Power Supply and optional Battery Back Up unit (BBU)

The power supply itself can consist of the minimum of one plug-in module or the maximum of four. Each module can provide up to 267W to the computer’s power requirements (see chapter 10 of the Owner's Handbook for further information). If there is more than one Power Module, the computer may be able to continue to operate if one module should fail, depending upon the configuration. When considering any additions to the computer hardware, the power requirements should be assessed prior to their installation.

When the BBU is fitted, the complete power supply becomes an uninterruptible power supply (UPS) and is designed to keep your system powered up for a limited period of time after, or during, a power failure. The optional on-line removable BBU will provide time to shutdown the network and the server without losing valuable data.

The UPS should maintain power to the system for approximately 4 minutes in a fully-laden system, i.e. equipped with 20 hard disk drives. This time will be much longer in a system equipped with fewer drives.

Note
In the event that the mains power fails, the LCD will display a countdown of the number of seconds remaining until the (optional) battery back up unit is fully discharged. The Event Manager User’s Guide contains more details about this feature.

Module Power Output

The power section is, in total, rated at: (output of 3 modules at 267W per module)


+5V rail at 81A
+12V rail at 33A
-5V rail at 500mA
-12V rail at 500mA
5V standby rail at 800mA

The above ratings are for three power modules, the fourth being a ‘redundant’ module.

The first two are for the busbars for the motherboard and the hard drive power board, the rest are taken via the multiway cables to their various destinations. Adding hard drives, extra processors or multiple expansion cards may require the addition of further power modules, contact your Apricot supplier for details.

Removing and fitting power modules

The power tray will be fitted with at least one power module, or up to a maximum of four.

Depending on the system configuration and the number of working modules fitted, one power module may be removed without shutting down the whole system, providing the remaining power modules can cope with the system load. See above for power module rating information.

It is advisable, if unsure, to fit a spare unit first if the computer cannot be shut down. The modules can be hot-swapped.

Any failed unit will display a red LED on its rear plate, or be completely unlit, while healthy units display a green LED. The modules are easily removed and fitted.

To remove a module

Loosen the floating fasteners, located at the top and bottom of the module to be removed, until they move in and out freely.

These fasteners are mounted in a spring fitting and should not be separated from the module.

Gently but firmly pull on the handle until the module slides out. There will be some resistance from the rear socket.

Power Module removal and refitting

To fit a module

Carefully slide the module into the internal guide rails and press firmly into the rear socket.

Fix into position with the retaining fasteners. Do not overtighten.

If the module is being fitted to a live system, the red LED will initially show during the unit’s self test. Then the green LED will come on to indicate the module is working correctly. If the computer has been powered down, all modules will briefly show red LEDs on power-up.

Removing the complete Power Tray

Warning
There are very few circumstances that would require the removal of the Power Tray, but details are given here for completeness. It is recommended that work on the tray should only be undertaken by a service engineer, with someone to assist, as the tray is very heavy.

It is vitally important to ensure that the system is correctly shut down. If a BBU is fitted, the battery link must be removed and the system disconnected from the mains electricity supply.

Remove the motherboard cooling fan assembly as detailed in chapter 8 of Owner's Handbook.

First detach two pairs of motherboard busbars and then the set of 3 busbars under the cooling fan assembly as shown in the following diagram.

If necessary, remove some of the expansion cards to improve access to the busbars. You may also need to unplug some of the data cables which are connected to the hard disk drive modules.

1 Motherboard Busbars 2 Busbars for Hard Disk Power Distribution Panel

Busbars

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, plugs and hard disks are as they were originally, you risk losing all the data on your hard disks.

Make sure that there is enough clearance between the busbars and their power supply connections to allow the unit to slide freely, you may need to remove the busbars completely.

Unplug three cables from the power supply as shown over.

1 System Controller Connector (Ribbon) 2 Motherboard Auxiliary Power (16-way) 3. Not used 4 Removable Media Bay Connector (12-way) 5 Cable Connector Group

Disconnecting Power Supply Cables

Loosen four floating fasteners, two on each side of the server, until they are free of the power supply unit, as indicated in the next illustration.

Warning
This Power supply is heavy. It is strongly advised to have a second person to assist before either fully removing the assembly from the server, or picking it up to fit it back into the server.

1 Floating Fasteners 2 Front Bezel

Power Supply Floating Fasteners

Now remove six screws on the back panel of the server, as shown:

Power tray Securing Screws

Using one or two of the handles, pull the unit carefully forward about 8 to 10cm, until a set of concealed busbar bolts become visible through one of the motherboard chamber busbar windows. Remove these bolts.

Continue pulling, this time using the main PSU flange, until it is a little less than halfway out (about 30 cm), just before it begins to tip towards you.

The second person should assist, on the opposite side of the unit, from this point onwards.

Place your hands under the metal casing of the unit as indicated by the arrows in the following illustration:

Power tray Removal

Slide the unit out slowly until it is free from its housing. Now rest the unit on the floor or a suitable workbench. Do not drop it.

Fitting

With the help of the second person on the opposite side, place your hands underneath the power supply as indicated by the arrows in the illustration above.

Now carefully slide the unit almost all the way into the chassis.

Use the front motherboard chamber busbar window to fix the bolts that hold the power distribution board to the output connections of the power tray. Then slide the tray fully in.

Caution
The hardware used to hold the busbar connections must be tightened using a torque wrench set to 5 Newton meters (Nm).

Secure the unit to the chassis with the six screws as shown in Figure 10-6.

Now tighten the four floating fasteners, two on each side, located towards the front of the machine.

Plug the cables into their connectors on the power supply.

Note that these connectors are keyed and can only be fitted in one position.

Attach the set of 3 busbars to the HDD power board. Then attach the two pairs of busbars to the motherboard.

As with the cables, it should not be possible to fit these bars incorrectly.

Fit the motherboard cooling fan assembly.

Refit any expansion cards you may have removed to improve access.

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, plugs and hard disks are as they were originally, you risk losing all the data on your hard disks.

Optional Battery backup unit (BBU)

Warning
The power supply tray can be equipped with an optional BBU. Although it is a replaceable unit, (information on removal and refitting is given below) it MUST ONLY BE FITTED, or removed, by a suitably qualified service engineer.

Initial installation of the unit MUST only be carried out by a service engineer visit to correctly setup the system to accommodate a BBU. Contact your Apricot supplier for details.

Initial installation

Only be undertaken by a service engineer.

Shut down the system and disconnect from the supply.

Remove the blanking plate but retain the fixing screws.

Reach inside the BBU space and detach the small printed circuit board from the clip-in mounting (this may be easier with a long screwdriver, due to limited space).

Disconnect the wiring harness from the rear BBU edge connector and remove the assembly from the chassis completely.

Fit the BBU into the power tray as detailed on the following page.

Important - Warning

The battery pack contains lead acid batteries. In the EEC the directive 91/157/EEC (plus subsequent amendment 93/86/EEC) designates batteries containing lead to be handled as a dangerous substance.

Similar regulations will apply in other countries.

The battery pack must only be removed by a qualified electrician and must not be disposed of in domestic waste.

Removing

Ensure the system is shut down as detailed in chapter 3.

Ensure that you remove the BBU isolation link.

Remove the fastening screws as shown in the following diagram:

INSERT DIAG HERE

Battery Backup Unit

Pull the BBU handle carefully. There will be initial resistance due to the power connector at the rear. Slide the unit out slowly . It is heavy.

Now with a slight lift, you can remove the BBU clear. Place it only on a clear flat surface.

Warning

The BBU even when withdrawn may still contain a high charge. Handle with extreme care.

Fitting

Carefully lift the BBU into position and slide it slowly into the chassis.

Push the unit the rest of the way into the chassis.

Press firmly into the socket.

Refit the retaining screws as shown in the above Figure 10-8.

Fit the BBU isolation link.

Battery Isolation (Fireman’s Switch)

The BBU link can be used to connect to the Building Fire Services power isolation and safety mechanisms if required. This is a common for big buildings or businesses having telephone exchanges and air conditioning etc., but often overlooked within large computer installations and networks.

The BBU isolation link is essentially a mini-plug, complete with cable grip, having the two small pins internally connected. This connection can be broken and the terminals wired to external cabling.

Screened cable should be used to connect to the isolation switch or power panel relay, which should have a normally closed (healthy) contact. For further information contact either your supplier, or Apricot Computers Limited, Technical Support department.

System management controller (SMC)

Removing

Take careful note of where each connection is from and unplug three ribbon cable connectors, the power connector, three fan connectors, two thermistor connectors and one keylock sensor cable connector as shown in the following diagram.

1 Power Connector 2 Fan Connectors 3 Thermistor Connectors 4 Keylock Sensor Connector 5 Securing Screws 6 Ribbon Cable Connectors

System Management Controller Board

Remove the securing screws detailed above.

Carefully unplug the SMI2C daughterboard and put in a safe place.

Remove the four stand-off screwlock pillars from the SMC board that are used to mount the SMI2C daughterboard.

Remove the two screw lock posts on the 25-way SMC serial port connector which is visible on the server’s back panel and lift the SMC board clear.

1 Screw Lock Posts 2 Back panel

SMC Serial Port Screw Lock Posts

Fitting

Feed the 25-way serial port connector through the opening in the back panel.

Fasten the board to the centre spine using the four screwlock stand-off pillars as previously removed.

Fasten the two screwlock posts into place at both ends of the 25-way connector on the back panel. Do not overtighten.

Plug in the SMI2C daughterboard to the top left sockets of the SMC.

Refit the remaining screws as shown in Figure 6-1.

Plug the ribbon cables, power cable, fan and associated thermistor cables and the keylock sensor cable into their respective connectors on the SMC board as shown in Figure 6-1.

Ensure the daughterboard is correctly seated on the connectors at the top left of the SMC board and that the correct two ribbon cables are fitted to the sockets on it.

Caution
Ensure the ribbon cables from the front panel and the PSU are in their correct positions or damage will be caused to the SMC board.

Against each fan connector on the board there is a graphic which indicates which fan cable should be plugged in:

The middle and bottom fans in this series are located below the SMC board in the disk subsystem area.