Replacing Parts



This chapter explains how to:

You can replace the following parts:

In addition, you can replace the following cables:

Note - Part numbers for the parts are listed in Appendix B, "Illustrated Parts Breakdown."

Preparing to Replace parts

Before you replace parts, make sure you have:

Turning Off Power

To turn off power, do the following:

    1. Halt the computer system.
      a. Type su and press Return to become the superuser.
      b. Type your superuser password and press Return.
      c. Type halt and press Return. 
---------------------------------------------------

tutorial% su
Password: Enter superuser password
tutorial# halt
Type b(boot), c(continue), or n(new command mode)
> 

---------------------------------------------------
    2. When you see the prompt, turn the power switches off (O position) in any order on the computer, monitor, SBus Expansion Subsystem, and all other peripherals.
    3. Check that the green lights on the front of the computer system and the SBus Expansion Subsystem are not lit and the computer system fan is not running.

Removing the Cover

Figure 5-1 shows how to remove the SBus Expansion Subsystem cover. Three tabs on the front of the cover fit into three slots in the chassis. These tabs secure the front of the cover to the chassis. A security loop secured to the cover goes through the bottom of the chassis.

Caution -

Make sure that the power to the SBus Expansion Subsystem is off (the green LED should not be lit). Do not disconnect the power cord from the power outlet of the SBus Expansion Subsystem or from the wall socket. This connection provides the ground path necessary to safely remove and install the printed circuit boards and parts.

To remove the cover, do the following:

    1. Turn off the power.

    See the previous section "Turning Off Power." Make sure that the power cord remains plugged into the SBus Expansion Subsystem and to the power source.

    2. Use a Phillips screwdriver to remove the two screws from the top corners of the back panel. Refer to Figure 5-1.
    3. Grasp the sides of the cover from the rear. Tilt the cover until the security loop clears the chassis.
    4. Gently push the cover forward about 1/2 inch (13 mm) so that the plastic tabs clear the chassis.

Caution -

Be sure the tabs clear the chassis before removing the cover.

    5. Lift up to remove the cover.

    Figure 5-1 Removing the Top Cover

Warning -

Before turning the power to the SBus Expansion Subsystem on again, be sure to replace the top cover. See "Replacing the Cover." It is not safe to operate the SBus Expansion Subsystem without the top cover in place.

Note - Keep the SBus Expansion Subsystem power cable plugged into the ac power source to supply a ground path for the wrist strap.

Attaching a Wrist Strap

The wrist strap provides grounding for static electricity between your body and the chassis of the SBus Expansion Subsystem. Electric current and voltage do not pass through the wrist strap. Attach the wrist strap to your wrist and to the metal case of the power supply in the SBus Expansion Subsystem.

Caution -

Boards, cards, and modules can be damaged by harmful electrical charges if you do not wear a wrist strap.

To attach the wrist strap, do the following:

    1. Unwrap the first two folds of the wrist strap. Wrap the adhesive side firmly against your skin.

    2. Peel the liner from the copper foil at the opposite end of the wrist strap.
    3. Attach the end with the adhesive copper strip to the metal casing of the SBus Expansion Subsystem power supply.

    Figure 5-2 SBus Expansion Subsystem layout

Removing and Replacing SBus Expansion Subsystem Parts

This section describes how to remove and replace SBus Expansion Subsystem parts. Read the entire set of instructions through before removing and replacing a part.

Figure 5-3 shows the main SBus Expansion Subsystem parts. The SBus Expansion Subsystem controller board is located in the left rear area of the chassis. SBus cards plug into the SBus Expansion Subsystem controller board.

The left front area of the chassis is reserved for two hard disk drives.

The power supply is mounted at the right-rear of the chassis.

    Figure 5-3 The SBus Expansion Subsystem and its main parts

Figure 5-4 shows the replaceable parts.

    Figure 5-4 Replaceable parts

SBus Cards

The SBus Expansion Subsystem can be equipped with a variety of SBus cards. To remove or install an SBus card into the SBus Expansion Subsystem, refer to the manual Installing SBus Cards in Desktop SPARCstations.

Expansion Adapter Card

To remove and replace the Expansion Adapter card in the computer system, follow the procedure in the manual Installing SBus Cards in Desktop SPARCstations. For all supported systems, install the cards in order starting with the lowest SBus Expansion Subsystem slot number.

Power Supply

The power supply is a self-contained metal assembly. It is located at the right- rear of the chassis (refer to Figure 5-5). The recess in the bottom of the chassis is for the fan that is built into the power supply.

The power supply is held in place by the following:

A 12-pin power cable connects the power supply to the SBus Expansion Subsystem controller board. Refer to Figure 5-5.

    Figure 5-5 Removing and replacing the power supply

Removing the Power Supply

To remove the power supply system, use the following tools and perform these steps:

    1. Halt your computer system, then turn off power to all units.

    Refer to "Turning Off Power."

Warning -

Turn the power switch to the off position on your SPARCstation and unplug the SBus Expansion Subsystem from the wall outlet before you before you remove, replace, or install the power supply. Failure to take this precaution may result in severe electrical shock.
    2. Remove the power cord from the SBus Expansion Subsystem and from the wall outlet.
    3. Remove the top cover of the SBus Expansion Subsystem. Refer to the Section "Removing the Cover."
    4. Remove the power supply securing screw from the back panel. Refer to Figure 5-5.
    5. Disconnect the power supply cable from the white 12 pin connector on the SBus Expansion Subsystem controller board.
    6. Grasp the power supply. Slide it forward toward the front of the chassis. Lift it out of the chassis.

Inserting the Power Supply

To install a new power supply in your desktop system, use the following tools:

Perform these steps:

    1. If your computer is not already off, halt your computer system then turn off power to all units.

    Refer to the Section "Turning Off Power."

Warning -

Turn the power switch to the off position on your SPARCstation and unplug the SBus Expansion Subsystem from the wall outlet before you before you remove, replace, or install the power supply. Failure to take this precaution may result in severe electrical shock.
    2. If necessary remove the top cover. Refer to "Removing the Cover."
    3. Align the power supply correctly with the tabs and guides in the bottom of the chassis. Refer to Figure 5-5.
    4. Position the power supply by pushing it firmly toward the rear of the chassis until it locks into the tabs.
    5. Connect the power cable to the white 12-pin connector on the SBus Expansion Subsystem controller board.

    The connector is keyed so that the power cable will fit only one way. Refer to Figure 5-5.

    6. Install the power supply securing screw through the back panel of the SBus Expansion Subsystem.

    This secures the power supply to the chassis. Refer to Figure 5-5.

    7. Replace the cover.

    Refer to "Replacing the Cover."

    8. Connect the power cord to the back of the unit and to the wall outlet.
    9. Turn the power switches on (| position) in this sequence:
      a. Peripherals attached to the SBus Expansion Subsystem
      b. SBus Expansion Subsystem
      c. Peripherals attached to the computer system
      d. Computer system
      e. Monitor
    10. Check for proper operation of the SBus Expansion Subsystem and the newly installed power supply.

    If the newly installed power supply does not work properly, a problem, such as a blown component or a short circuit, can exist in the SBus Expansion Subsystem.

Hard Disk Drive

To remove and replace a hard disk drive, refer to the disk drive manual you received with your disk drive.

SBus Expansion Subsystem Controller Board

The SBus Expansion Subsystem controller board contains the following:

Figure 5-6 shows the connectors and other parts on the SBus Expansion Subsystem controller board.

    Figure 5-6 SBus Expansion Subsystem Controller Board layout

Caution -

Make sure that the power on your SBus Expansion Subsystem is turned OFF. Check that the green light at the front of the chassis is not lit and that the power supply fan is not running.

Caution - Do not disconnect the power cord from the power outlet of the SBus Expansion Subsystem or from the wall outlet. This connection provides the ground path necessary to safely remove and install the boards. Boards, cards, and modules can be damaged by harmful electrical charges if you do not wear a wrist strap.

Caution -

Printed circuit boards are made of delicate electronic parts that are extremely sensitive to static electricity. Ordinary amounts of static from your clothes or work environment can destroy the parts on the boards. Always wear a wrist strap when handling the boards.

Caution - Handle boards only by the nonconducting edges. Do not touch parts or any metal parts.

Removing the SBus Expansion Subsystem Controller Board

To install a new SBus Expansion Subsystem Controller Board in your desktop system, use the following tools:

To remove the SBus Expansion Subsystem controller board, do the following:

    1. Halt your computer system, then turn off power to all units.

    Refer to the Section "Turning Off Power."

    2. Remove the cover.

    Refer to the Section "Removing the Cover."

    3. Attach a wrist strap.

    Refer to the Section "Attaching a Wrist Strap."

    4. Disconnect all the cables from the connectors on the rear of the unit.
    5. Place an antistatic mat next to the SBus Expansion Subsystem.
    6. Remove the SBus cards.

    Refer to the Section "SBus Cards."

    7. Disconnect the power supply cable from the connector in the right front corner of the board. Refer to Figure 5-7.
    8. Disconnect the LED cable from the connector in the right front corner of the board. Refer to Figure 5-7.
    9. If you installed one or more disk drives, disconnect the hard disk drive power and data cables from the appropriate connectors on the board. Refer to Figure 5-7.

    Fold them out of the way.

    10. Use your phillips screwdriver and remove the two screws that secure the board to the back panel. Refer to Figure 5-7.
    11. Tilt up the side of the board next to the power supply and slide it towards the front of the chassis.

    This action releases it from the five standoffs in the bottom of the chassis and clears it from the overhang on the side of the box.

    12. Grasp the board by the SBus slot connectors with both hands. Lift it out of the chassis.

    Avoid touching any circuitry or parts on the board.

    13. Place the board on an antistatic mat.

    Figure 5-7 Removing and replacing the SBus Expansion Subsystem controller board

Replacing the SBus Expansion Subsystem Controller Board

To replace the SBus Expansion Subsystem controller board, do the following:

    1. Halt your computer system then turn off power to all units.

    Refer to "Turning Off Power."

    2. Remove the cover.

    Refer to "Removing the Cover."

    3. Attach a wrist strap.

    Refer to "Attaching a Wrist Strap."

    4. Align the board so that the five tapered mounting holes align with the standoffs in the bottom of the chassis.
    5. Insert the connectors on the rear of the replacement board into the back panel.

    Refer to Figure 5-7.

    6. Slide the board back toward the back panel so that the connectors are aligned with the openings in the back panel.

    The standoffs should lock into the mounting holes.

    7. Replace the two screws that secure the board to the back panel.

    Refer to Figure 5-7.

    8. Connect the power supply cable to the power supply connector in the right-front corner of the board.

    The connector is keyed so that the power cable will fit only one way.

    9. If you installed disk drives, connect the disk drive data cables from the old SBus Expansion Subsystem controller board to the connectors on the new controller board.

    Route the cables appropriately.

    10. If you installed disk drives, connect the hard disk drive power cables to the appropriate connectors on the SBus Expansion Subsystem controller board.

    Refer to Figure 5-7. The connectors are keyed so that they will only fit one way.

    11. Connect the LED cable assembly to the connector in the right front corner of the board.
    12. Reinstall the SBus cards.

    Refer to the Section "SBus Cards."

    13. Disconnect and remove the wrist strap.
    14. Replace the cover.

    Refer to "Replacing the Cover."

    15. Connect all of the cables to the connectors at the rear of the unit.
    16. Turn on power to all devices.

    Refer to "Turning Power On."

Replacing the Cover

To replace the cover, do the following:

    1. Hold the cover at approximately a 30 degree angle in relation to the SBus Expansion Subsystem chassis.

    The front end should be down and the back end should be up. Gently guide the plastic tabs on the front of the cover into the tab slots on the front of the chassis. Continue to hold the cover.

Caution -

Holding the cover at angles greater than 30 degrees can prevent inserting the tabs into the tab slots. Once the tabs are in the slots, raising the cover to angles greater than 30 degrees can break the tabs.

    2. Slowly lower the cover onto the chassis.

    Be sure the security loop seats into the security loop slot on the bottom of the chassis. Make sure the cover fits over the ends of the back panel.

    3. Use a Phillips screwdriver to insert and tighten the two screws at the top of the back panel

    .

    Figure 5-8 Replacing the SBus Expansion Subsystem cover

Warning - Make sure you replace the cover and secure it before you power up the SBus Expansion Subsystem. Failure to take this precaution may result in personal injury and damage to the SBus Expansion Subsystem. Do not block vents on the sides or rear of this unit; permanent damage may occur.

Turning Power On

Warning -

This device is equipped with one 3-wire grounded power cord. To reduce the risk of electrical shock, always plug the power cord into a properly grounded power outlet.

Caution -

Always allow 10 seconds between turning off the power and turning it back on again. This pause prevents possible damage to power supply parts in your SBus Expansion Subsystem.

    1. Turn the on/off switches on (| position) in this order:
      a. Devices connected to the SBus Expansion Subsystem
      b. SBus Expansion Subsystem
      c. Devices connected to the computer system
      d. Computer system
      e. Monitor