User Guide

Removing/Replacing Parts

   Removing the Top Cover

4. Slide the top cover panel back approximately � inch. Lift it straight up and away from the chassis.
5. Loosen the 2 thumbscrews securing the side panels to the chassis.
6. For each side cover panel, slide the panel approximately � inch toward the back of the computer, pivot it down a few inches, disengage the hooks at the bottom, and lift the panel away from the chassis.

   Removing the Side Cover

7. To reinstall the cover panels, follow steps 1 through 6 in reverse.

NOTE: The right- and left-side cover panels are identical and can be installed on either side of the computer.

Removing/Replacing the Front Bezel
1. Turn off the power, and unplug the power cable.
2. Remove the cover panels. See Removing/Replacing Cover Panels.
3. Remove the front bezel.

   Facing the computer's front panel, spread the 2 top tabs (1 on each side) of the front bezel until it   
   disengages from the chassis.  Then tilt the bezel, disengage the hooks at the bottom, and pull it away   
   from the chassis.

   Removing the Front Bezel

4. To replace (or reinstall) the bezel, fit the 2 retaining hooks at the bottom of the bezel into the 2 slots at the bottom of the chassis, and snap the bezel into place.

Removing/Replacing Front-Panel Components
Removing/Replacing the Control Panel Board
1. Turn off the system, and disconnect from power.
2. Remove the cover panels. See Removing/Replacing Cover Panels.
3. Remove the front bezel. See Removing/Replacing the Front Bezel.
4. Disconnect the control panel cable from the PANEL connector on the system board.
5. Remove the screw that secures the control panel board to the front of the chassis. Pull the control panel board away from the alignment pins on the front of the chassis.

   Control Panel Board

6. To replace (or reinstall) the control panel board, follow steps 1 through 5 in reverse.
7. Start the System Setup program, and verify that the configuration information is correct.

Removing/Replacing Front-Panel Inserts
Removing/Replacing 5.25-Inch Front-Panel Inserts
1. Turn off the system and disconnect from power.
2. Remove the cover panels and front bezel. See Removing/Replacing Cover Panels and Removing/Replacing the Front Bezel.
3. Hold the bezel (facing the inside of the bezel). Press outward with thumbs near the center of the insert until the insert bows out far enough to disengage one of the side tabs. Then press forward on the outside of the insert, over the disengaged tab, to release the insert.

   Removing the 5.25-Inch Insert

4. To replace (or reinstall) the insert, align it on the inside of the bezel and snap it into the opening.
5. Replace the front bezel.
Removing/Replacing the 3.25-Inch Insert
1. Turn off the system and disconnect from power.
2. Remove the cover panels and front bezel. See Removing/Replacing Cover Panels and Removing/Replacing Front Bezel.
3. Hold the bezel facing its interior surface. Spread the retaining tabs slightly, and pop the insert inward.

   Removing the 3.25-Inch Insert

Installing/Removing Expansion Cards
ISA and VL-Bus expansion cards fit horizontally into connectors on the ISA riser board and VL-Bus riser board, respectively. The riser boards connect to the system board via the bridge board that mounts horizontally along the top of the riser-board mounting bracket.

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the top and right-side cover panels. See Removing/Replacing Cover Panels.
3. Disconnect any cables from the expansion card.
4. Unscrew the retaining screw from the card-mounting bracket.

   Installing an ISA Expansion Card

5. Grasp the card by its corners, and carefully pull it out of its expansion-card connector.

   Rock the card out of its connector while removing the metal card-mounting bracket from the card-slot    
   opening on the back panel of the chassis.

6. To replace (or reinstall) a card, follow steps 1 through 5 in reverse.

Removing/Replacing the Card Guide Assembly

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the top and right-side cover panels. See Removing/Replacing Cover Panels.
3. Remove any installed expansion cards.
4. If there is an auxiliary speaker, disconnect it from the SPKR connector on the system board.
5. Remove the card guide assembly.

   Card Guide Assembly

The assembly is secured by a plastic tab that snaps through a slot in the front of the chassis.

   To remove the card guide, press in on the tab from the front while pulling the card guide out the right 
   side of the system unit.

6. Replace (or reinstall) the card guide assembly; then follow steps 1 through 5 in reverse.

Removing/Replacing the ISA Riser Board

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the top and right-side cover panels, and then the front bezel. See Removing/Replacing Cover Panels and Removing/Replacing the Front Bezel.
3. Remove any expansion cards installed on the riser board.
4. Remove the ISA riser board from the riser board bracket.

   Remove the 4 screws that secure the riser board to the bracket.  Then grasp the riser board by its      
   sides, and carefully pull it away from its bridge board connection.

   Removing ISA Board from Bracket

CAUTION: The bridge board is susceptible to damage from pressure on either side if it is not braced on the opposite side. Never install a board onto the bridge board (from either side) without making sure the bridge board is supported on the opposite side

either by hand or by an installed system board or riser board.

5. To replace (or reinstall) the ISA riser board on the bracket, follow steps 1 through 4 in reverse.
6. Insert the diagnostics diskette into drive A, and run the System Set Test Group to verify that the computer system operates correctly.

Removing/Replacing the VL-Bus Riser Board

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the top and right-side cover panels. See Removing/Replacing Cover Panels.
3. Remove any expansion cards installed in the ISA1 and ISA2 connectors.
4. Remove the VL-Bus riser board from the bracket.

   Unscrew the 2 screws that secure the riser board to the bracket.  Grasp the riser board by its sides,   
   and carefully pull it away from its bridge board connection.

   Installing the VESA Riser Card

5. To replace (or reinstall) a VL-Bus riser board, follow steps 1 through 4 in reverse.

CAUTION: The bridge board is susceptible to damage from pressure on either side if it is not braced on the opposite side. Never install a board onto the bridge board (from either side) without making sure the bridge board is supported on the opposite side

either by hand or by an installed system board or riser board.

6. Insert the diagnostics diskette into drive A, and run the System Set Test Group to verify that the computer operates correctly.

Removing/Replacing the Bridge Board Assembly
CAUTION: The bridge board is susceptible to damage from pressure on either side if it is not braced on the opposite side. Never install a board onto the bridge board (from either side) without making sure the bridge board is supported on the opposite side

either by hand or by an installed system board or riser board.

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the top and left-side cover panels. See Removing/Replacing Cover Panels.
3. Remove the system board assembly. See Removing/Replacing the System Board Assembly.
4. Remove any expansion cards installed on the riser boards.
5. Remove the riser boards.
6. Remove the bridge board assembly.

   Remove the 3 screws that secure the bridge board bracket to the side of the riser-board mounting        
   bracket.  Then lift the assembly out of the computer.

   Removing the Bridge Board Assembly

7. To replace (or reinstall) the bridge board assembly, follow steps 1 through 6 in reverse.

CAUTION: The bridge board is susceptible to damage from pressure on either side if it is not braced on the opposite side. Never install a board onto the bridge board (from either side) without making sure the bridge board is supported on the opposite side

either by hand or by an installed system board or riser board.

8. Insert the diagnostics diskette into drive A, and run the System Set Test Group to verify that the computer operates correctly.

Removing/Replacing Cache Memory Chips

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Disconnect any peripheral device cables attached to the port connectors on the I/O panel.
3. Remove the top and left-side cover panels. See Removing/Replacing Cover Panels.
4. Remove the system board assembly from the computer, and lay it on a flat surface to work on it. See Removing/Replacing the System Board Assembly.
5. Locate the cache-memory upgrade, buffer, or directory sockets (U2, U52, U55, U57, U59, U60, and U68) on the system board.

   Cache-Memory Upgrade Sockets

6. Note the location and orientation of each cache memory chip being removed, and then use a chip-removal tool to remove the chip.
7. To replace (or reinstall) each cache memory chip, follow steps 1 through 6 in reverse.

       The 2 20-pin cache-buffer chips (U55 and U57) are interchangeable.

       The part number of the 28-pin cache-directory chip (U2) ends in -15.

       The 4 cache-memory chips are interchangeable.

8. Start System Setup, and verify that the EXTERNAL CACHE category displays 128 KB.
9. Insert a diagnostics diskette into diskette drive A, and run the System Set Test Group in the diskette-based diagnostics to verify that the system operates correctly with the new chips.

Installing/Removing SIMMs

NOTE: This procedure assumes that one is facing the back of the computer.

Removing a SIMM
1. Turn off the system, and disconnect from power.
2. Disconnect any peripheral device cables attached to the port connectors on the I/O panel.
3. Remove the top and left-side cover panels. See Removing/Replacing Cover Panels.
4. Remove the system board assembly from the computer, and lay it on a flat surface to work on it. See Removing/Replacing the System Board Assembly.
5. Remove the SIMM.

   While pushing outward on each of the SIMM socket's metal tabs, rotate the SIMM downward (toward RISER_2) 
   until it is released from its socket.

   Removing the SIMM

Replacing a SIMM
1. Locate the cutout area on one corner of the SIMM, and position it with its cutout pointing toward the I/O panel on the system board assembly.

   Installing a SIMM

2. Press the SIMM's card-edge connector firmly into the SIMM socket, and rotate the SIMM in the direction of the arrows until it snaps into place.
3. Reinstall the system board assembly.
4. Check all cable connections inside the system unit to ensure that they have not been loosened.
5. Reinstall the cover panels.
6. Reconnect any peripheral device cables that were disconnected.
7. Reconnect the computer to power and turn it on.
8. Verify the system configuration information.
9. Insert a diagnostics diskette into diskette drive A, and run the RAM Test Group in the diskette-based diagnostics to verify that the SIMMs operate correctly.

Removing/Replacing the Microprocessor

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Disconnect any peripheral device cables attached to the port connectors on the I/O panel.
3. Remove the top and left-side cover panels. See Removing/Replacing Cover Panels.
4. Remove the system board assembly from the computer, and lay it on a flat surface to work on it.
5. Remove the heat sink from the microprocessor chip.

   Use a small screwdriver to pry up one end of the securing sink clip.  Remove the heat sink and the      
   graphite insulating pad from the chip.

   Removing the Heat Sink

6. Use a chip-removal tool to remove the chip from its socket.

   Removing the Microprocessor Chip

NOTE: The 100-MHz SL Enhanced IntelDX4 microprocessor is permanently mounted on a daughter board that contains a voltage regulator. To remove it, insert the tool under the daughter board and carefully pry the board from the microprocessor socket.

7. To replace (or reinstall) the chip, orient it so that its pin-1 corner matches the pin-1 corner of the socket.

   Pin-1 Identification (IntelDX2, IntelSX)

Pin-1 Identification (IntelDX4)

8. Insert the chip, and press it into its socket until it is firmly seated.

       IntelDX2 and IntelSX2 chips must be centered in the socket, with an empty row of holes showing    
       around all 4 sides of the chip.

       For IntelDX4 chips, align the row of holes and pins closest to what will be the bottom of the     
       system board when the board is installed.  A row of empty holes should remain on the side of the   
       socket that faces the cache-memory upgrade sockets.

9. Install the new insulating pad, heat sink, and clip.

   Fit the 2 ribs on the underside of the heat sink around the chip; then align the notches in the heat    
   sink with the other 2 sides of the chip.  Hook one end of the clip through one of the notches; then press 
   the other end down until it snaps into place.

10. Check the microprocessor speed jumper setting. See Jumpers.
11. Perform steps 1 through 4 in reverse.
12. Enter System Setup, and confirm that MICROPROCESSOR and CPU SPEED correctly identify the installed microprocessor.
14. Insert the diagnostics diskette into drive A, and run the System Set Test Group to verify that the microprocessor is operating correctly.

Removing/Replacing the Backup Battery

NOTE: This procedure assumes that one is facing the back of the computer.

1. Make a copy of the system configuration information in System Setup.
2. Turn off the system, and disconnect from power.
3. Remove the top and left-side cover panels. See Removing/Replacing Cover Panels.
4. Partially remove the system board assembly to access the backup battery.

   Remove the 2 screws that secure the system board assembly to the chassis.  Rotate the system board out  
   and down, disconnecting the RISER connector (and the RISER_2 connector, if in use) from the bridge board. 
    With the board in a tilted position, locate the backup battery

5. Remove the backup battery.

   Pry the battery out of its socket with a blunt, nonconductive object such as a plastic screwdriver.

   Backup Battery and Socket

6. To replace (or reinstall) the backup battery, follow steps 1 through 5 in reverse.

   Orient the battery with the side labeled "+" facing up.  Insert the battery into the socket and 
   snap it into place.

7. Enter System Setup, and reset the TIME and DATE categories.
9. Turn off system, and unplug it for 10 minutes.
10. Turn on the computer, and enter System Setup. If TIME and DATE are still incorrect, get technical assistance.

Removing/Replacing Drives in the Drive Cage
Drive Hardware

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the cover panels and front bezel. See Removing/Replacing Cover Panels and Removing/Replacing the Front Bezel
3. Disconnect the DC power cable and interface cable from the back of the drive.
4. Press in on the plastic drive rail tabs on each side of the drive, and slide the drive out of its bay.

   Installing a Drive in the Drive Cage

5. To replace (or reinstall) the drive, follow steps 1 through 4 in reverse.

   Prepare the drive for installation; attach drive rails, if necessary.

   Attaching Drive Rails

6. See Verifying Drive Operation after the drive installation.

Removing/Replacing Drives in the 3.5-Inch Drive Bracket

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the cover panels and front bezel. See Removing/Replacing Cover Panels and Removing/Replacing Front Bezel.
3. Disconnect the DC power cable and interface cable from the back of the drive.
4. Unscrew the screw that secures the front of the 3.5-inch drive bracket to the computer.

   Removing the 3.5-Inch Bracket

5. Slide the 3.5-inch drive bracket out of the drive bay along the rails built in to the top of the drive bay.
6. Remove the 4 screws on the bottom of the 3.5-inch drive bracket, and slide the drive out of the drive bracket.

   Removing the Drive

7. To replace (or reinstall) the drive, follow steps 1 through 6 in reverse.

   Prepare the drive for installation.

6. See Verifying Drive Operation after the drive installation.

Removing/Replacing Hard-Disk Drive in a Bracket
Hard-Disk Drive Installed

NOTE: This procedure assumes that one is facing the back of the computer.

1. Back up the user's data to diskettes or tape, if possible.
2. Turn off the system, and disconnect from power.
3. Remove the top and right-side cover panels. See Removing/Replacing Cover Panels.
4. Disconnect the DC power and interface cables from the backs of all hard-disk drives installed in the drive bracket.
5. Remove the drive-bracket mounting screw, and then remove the drive bracket from the chassis. Swing the bracket out from under the power-supply bracket; then lift the drive bracket to disengage the mounting tabs on the back corner of the bracket from the chassis.

   Releasing the Hard-Disk Drive Bracket

6. Remove the 2 mounting screws from each side of the hard-disk drive bracket.

   Removing a Hard-Disk Drive

7. Slide the drive out of the hard-disk drive bracket.
8. To replace (or reinstall) the drive, follow steps 2 through 7 in reverse.

   2 hooks on the underside of the power supply bracket provide additional support for the drive bracket.  
   When swinging the drive bracket back under the power supply, lift it slightly and make sure the hooks    
   engage the top of the drive bracket.

Verifying Drive Operation
Verifying Diskette/Tape Drive Operation
1. Turn on the computer, and wait till the boot routine is complete.
2. Enter System Setup, and verify that DISKETTE DRIVE A and DISKETTE DRIVE B are set correctly for diskette drives. For a tape drive installed as a second drive, update the DISKETTE DRIVE B to NOT INSTALLED.
3. If the configurations are incorrect, make the corrections and reboot.
4. Insert a diagnostics diskette into the boot drive, and run the Diskette Drive(s) Test Group to verify that each diskette drive operates correctly.
Verifying Hard-Disk Drive Operation
1. Enter System Setup, and verify that the hard-disk drive categories are configured correctly.
2. If the configurations are incorrect, make the corrections and reboot.
3. For a replacement drive, partition and logically format the drive. Restore the user's files (if possible) to the drive.
4. Insert a diagnostics diskette into the boot drive, and run the Hard-Disk Drive(s) Test Group to verify that each hard-disk drive operates correctly.

Removing/Replacing the Power Supply
1. Turn off the system, and disconnect from power.
2. Remove the cover panels. See Removing/Replacing Cover Panels.
3. Disconnect the DC power cables from the system board, from any drives, and from any expansion cards.
4. Remove the 2 screws that secure the power supply to the chassis.

   Removing the Power Supply

5. Lift the power supply up and out of the power supply bracket.
6. To replace (or reinstall) the system power supply, follow steps 1 through 5 in reverse.

Removing/Replacing the System Board Assembly
The system board and the I/O panel are attached to the system-board mounting plate. This assembly is secured to the chassis by 2 screws and 2 tabs. Because of the location of the system board assembly, it must be removed to gain access to some system components.

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Remove the top and left-side cover panels. See Removing/Replacing Cover Panels.
3. Disconnect any peripheral device cables attached to the port connectors on the I/O panel.
4. Disconnect the system board assembly from the bridge board.

   Remove the 2 screws that secure the system board assembly to the chassis.

   While supporting the computer with one hand, grasp the system board assembly by the top edge and pivot  
   it out at the top, carefully disconnecting the bridge board connectors from the bridge board.  Leave     
   board in tilted position (attached at the bottom) while performing step 5.

   Removing the Assembly

5. Disconnect the following cables:

       Diskette/tape drive interface cable

       IDE cable

       Auxiliary hard-disk drive indicator cable

       DC power cable

       Auxiliary speaker cable

       Control panel cable

6. Remove the system board assembly from the chassis.
7. Replace (or reinstall) the system board assembly.

   Replacing the System Board

either by hand or by an installed system board or riser board.

   a.  Insert the 2 tabs on the bottom of the system-board mounting plate into the slots at the bottom of 
       the chassis.

   b.  With the board assembly in a tilted position, reconnect the system board cables that were removed 
       in step 5.

   c.  Rotate the system-board mounting plate toward the chassis until it stops.

       Position the right thumb over "Push here" on the right side of the plate, and place the   
       fingers in the card-slot opening at the back chassis wall.

       Position the left thumb over "Push here" on the left side of the plate while hooking one  
       finger on the riser-board mounting wall inside the chassis.

       Squeeze the right side of the plate with the right hand, and the left side of the plate with the  
       left hand, until the system board assembly snaps into place.  Squeeze until the bridge board       
       connector inserts into the riser connectors on the system board.

   d.  Reinstall the 2 screws that secure the system board assembly to the chassis.

8. Check that all cables are firmly connected.
9. Follow steps 1 though 3 in reverse.

Removing/Replacing the System Board
1. Perform steps 1 though 6 of Removing/Replacing the System Board Assembly.
2. Remove the 4 screws holding the system board to the mounting plate.

   System Board Mounting Screws

3. Slide the system board away from the I/O cover panel, disengaging it from the hooks in the mounting plate and from the I/O panel.
4. Replace (or reinstall) the system board on the mounting plate.

NOTE: Be sure to transfer SIMMs and cache-memory upgrade chips to the new board before installing.

   a.  Position the system board over the mounting plate, with the microprocessor at the bottom edge of  
       the mounting plate (next to the mounting tabs).

   b.  Place the system board over the hooks on the mounting plate;  then slide it toward the I/O cover  
       panel until the 4 sets of screw holes are aligned and the system board is engaged in the plastic   
       slots of the I/O cover panel.

   c.  Secure the system board to the mounting plate with the 4 screws removed in step

2.

NOTE: The screw located between RISER_2 and DSKT is longer and darker than the other 3 screws that secure the system board. Be sure to install this longer screw in the correct position when replacing the system board.

5. Perform steps 7, 8, and 9 of Removing/Replacing the System Board Assembly.
6. Start System Setup, and verify that the configuration information is correct.
7. Insert the diagnostics diskette into drive A, and run the System Set Test Group to verify that the new system board is operating correctly.
8. Update the service tag number.

Removing/Replacing the I/O Panel Cover

NOTE: This procedure assumes that one is facing the back of the computer.

1. Turn off the system, and disconnect from power.
2. Disconnect any peripheral device cables attached to the port connectors on the I/O panel.
3. Remove the top and left-side cover panels. See Removing/Replacing Cover Panels.
4. Disconnect any cables that are connected to the system board, and remove the system board assembly from the chassis. See Removing/Replacing the System Board Assembly.
5. Remove the system board from the mounting plate. See Removing/Replacing the System Board.
6. Remove the plastic I/O panel cover from the system-board mounting plate.

   Removing the I/O Panel Cover

2 plastic tabs on the I/O panel snap into notches in the mounting plate to secure the I/O panel.  Place 
   the fingers above 1 of the tabs and lift the I/O panel cover away from the mounting plate while pushing  
   the panel off the mounting plate.  Repeat this operation in the vicinity of the other tab to push the I/O 
   panel cover completely off the mounting plate.

7. To replace the I/O panel cover, align the plastic tabs on the I/O cover with the notches in the mounting plate, and slide the I/O panel cover into position.
8. To complete the procedure, follow steps 1 through 6 in reverse.