Acer Extensa 450 Maintenance Manual

							6.2.2   Protecting the Disk Drives
To protect the disk drives and data, back up the system disk periodically on floppy
diskettes. Periodically use a head-cleaning diskette in the floppy diskette drive to
prolong the life of the drive and to help maintain data integrity.
6.2.3   Handling the Computer Battery Pack
The battery pack furnished with the computer requires reasonable care and
handling to ensure efficient operation and maximum life. Periodically inspect the
battery terminals and the batteries for evidence of corrosion and oxide build-up;
clean if necessary.
To ensure that the battery pack endures a normal life cycle, always observe the
following precautions when handling the battery pack:
·Do not drop the battery pack or subject it to excessive shock and vibration.
·Do not expose the battery pack to direct sunlight, moisture, or chemical
compounds.
·Do not disassemble the battery pack.
·Do not use the battery pack to power other devices.
·Do not short the battery leads or connect the battery with reversed polarity. 
·Never attempt to charge the battery pack in any way other than as described in
this manual.
·Always charge the battery pack as soon as possible after a low battery
indication. 
6.2.4  Restoring System Software
The hard drive on the notebook computer is factory loaded with Windows 95 and
ready for operation. Supplied with the Windows 95 system is a facility for creating
backup diskettes of the system software. In the event of a disk crash or other
problem, you can use the Windows 95 Startup diskette to boot the unit and
perform troubleshooting.
6.3   Required Tools and Equipment  
All notebook computer corrective maintenance procedures can be performed using
the following tools: Tweezers
· Small flat-blade screwdriver
· Small Phillips screwdriver
· Hexagonal Screwdriver
· Plastic Stick
 
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							cCaution: All boards, options and peripherals contain components that
are sensitive to static electricity. When handling any of these items, pro-
tect against static electricity by using wrist or ankle grounding straps
and grounded working mats. When moving or storing items, use the anti-
static bags supplied with the items.
6.4  Notebook Field-Replaceable Parts
and Assemblies
All members of the Extensa 450 Series Notebook Computers contain two major
assemblies including the Cover Display Assembly (upper half of notebook computer)
and the System Base Assembly (lower half of the notebook). Each of these two
assemblies contain FRUs as described in the following subparagraphs.
6.4.1   Cover-Display Assembly
As shown in Figure 6-1, the Cover -Display Assembly contains the LCD screen,
Power Inverter Board, and Converter Board.,The DSSTN models also include a Slide
Pot Board (not used with the TFT models).
The Field Replaceable Units (FRUs) within the Cover Display Assembly  are provided
in Table 6-1.
nNote: FRU level part numbers are not available at time of publication of this man-
ual. For required part numbers, reference the Field Service Bulletins (FSBs) for the
Extensa 450 Series or contact Texas Instruments by dialing 1-800-TI TEXAS
. 
Bezel (Removed
for Clarity)
Power Inverter
Board
Slide Pot/Converter 
Board
LCD Cover
Figure 6-1   Cover Display Assembly FRUs
 
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							Table 6-1  Cover Display Assembly, Field Replaceable Units (FRUs)
FRU Description Reference 
Paragraph 
No.FRU Description Reference 
Paragraph 
No.
Inverter Board, DSSTN
10.46.5.9 LCD Cover, DSSTN
10.4, 4506.5.9
Inverter Board, TFT 9.4 6.5.9 LCD Cover, TFT 9.4,
450T6.5.9
Display Assembly, 10.4
DSSTN 4506.5.8 Bezel, DSSTN 10.4,
4506.5.9
Display Assembly, 9.4
TFT 450T6.5.8 Bezel, DSSTN 10.4,
4556.5.9
Slide Pot Board, DSSTN
10.4 6.5.9 Bezel, TFT 9.4,  450T 6.5.9
Converter Board, TFT
9.46.5.9 Bezel, TFT 9.4, 455T 6.5.9
6.4.2   System Base Assembly
As shown in Figure 6-2, the System Base Assembly houses a variety of
field-replaceable subassemblies and components. The FRUs and paragraph
references for removal/replacement procedures are listed in Table 6-2. Table 6-3
contains a listing of Customer (non-technical user) replaceable units (CRUs) and
associated TI Part Numbers.
nNote: FRU level part numbers are not available at time of publication of this man-
ual. For required part numbers, reference the Field Service Bulletins (FSBs) for the
Extensa 450 Series or contact Texas Instruments by dialing 1-800-TI TEXAS
.
Figure 6-2  Base Assembly FRUs
 
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							Table 6-2  Base Assembly, Field Replaceable Units (FRUs)
FRU Description Reference
Paragraph
No.FRU Description Reference 
Paragraph 
No 
Main Board Assembly 6.5.16 Touch Pad Assembly 6.5.11
Memory Board Assembly 6.5.15 Heat Sink Assembly 6.5.6
Serial IR Board Assembly 6.5.12 HDD Cable 6.5.4
Primary Battery Board
Assembly6.5.13 FDD Cable 6.5.4
Secondary Battery
Board Assembly6.5.17 HDD Cover Assembly 6.5.4
Power Supply Board
Assembly6.5.14 HDD Holder Assembly 6.5.4
Floppy Drive Assembly  6.5.3 Lower Case Assembly  Ref
Hard Disk Drive, 340
Million Byte, 12.5mm6.5.4 Upper Case Assembly  6.5.10
Keyboard Assembly 6.5.5
Table 6-3  Notebook CRUs (Customer Replaceable Units)
CRU Description TI Part No.  Reference
Paragraph
No.
Internal Battery Pack, Ni-MH 9803928-0001 6.5.1
Battery Pack, Li-ION (Option) 9803929-0001 6.5.3
4MB RAM Module 9803932-0001 6.5.7
8MB RAM Module 9803950-0001 6.5.7
16B RAM Module 9803933-0001 6.5.7
External Battery Charger 9803934-0001 Ref.
Port Expander (TravelBud) 9803935-0001 Sec. 2
Full Function Port Replicator 9803936-0001 Ref.
PCMCIA Option 9803930-0001 Sec. 2
 
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							6.5  Notebook Subassembly Removal
and Replacement Procedures
The following paragraphs contain field service-level removal/replacement
procedures for the Notebook.
cCaution: Prior to removing any of the internal FRUs in the notebook, re-
move the AC Adapter, battery, floppy and hard drives and all external op-
tions installed on the notebook.
6.5.1  Removing/Replacing the Notebook Battery
Pack
The procedure for removing and replacing the battery pack(s) is as follows:  
1. Turn off the computer. 
2.  Locate the battery door (right side of notebook near the front) (see Figure 6-3).
Press the battery door inwards and slide the door toward the front of the
notebook; remove the battery door.
3.  Grasp the ribbon loop on the battery and pull the battery out of the
compartment..
4.  When replacing the battery, insert the end opposite the ribbon loop with the
battery notches pointing upwards. Slide the battery into the compartment
and replace the battery door.
Figure 6-3  Removing Battery and Disk Drives
 
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							6.5.2   Removing/Replacing PCMCIA Options
The procedure for removing and replacing the PCMCIA options is as follows:  
1. Turn off  the computer.
2.  Remove the PCMCIA device(s).
3.  To replace the PCMCIA Device, open the cover door and insert the device.
Reinstall any external cabling required for the device. 
6.5.3  Removing/Replacing the Floppy Drive
To remove and replace the Floppy Drive,  perform the following procedure:
1.  Remove the battery as described in Paragraph 6.5.1 above.
2. Turn the notebook over so that the bottom is facing up and the floppy drive is on
the right side. Lay the notebook on a padded, flat work surface.
3. Locate the Floppy Release Button near the center of the notebook (Figure 6-3).
cCaution: When removing the Floppy Drive Assembly, grasp it by its
sides; otherwise damage to the floppy drive can occur.
4.  Push the Floppy Release Button toward the front of the notebook and
simultaneously pull outwards on the floppy drive by placing your thumb
over the ribbed outer edge of the floppy drive assembly. When the floppy
drive is released, grasp the assembly by the two sides and remove the
assembly from the notebook.
5.  The Floppy Drive Assembly can be further disassembled by removing the
Phillips-head screws from the sides of the floppy drive assembly; lifting off
the cover and lifting out the floppy drive and cable connector (ZIF Connector
type). Unplug the cable at the ZIF Connector .
nNote: When reassembling the floppy drive, it’s easier to install the shield on the
floppy drive before installing the drive into the plastic housing.
6.5.4  Removing/Replacing the Hard Drive 
The procedure for removing and replacing the Hard Drive assembly is as follows:  
1. Power down the notebook, remove the battery packs, and disconnect the AC
Adapter, if installed.
2. Disconnect any peripheral device interface cables from the external interface
connectors and remove any installed PCMCIA options. 
 
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							3. Turn the computer over so that the Hard Drive panel is on your right side (See
Figure 6-3). Press down on the circular bump with your thumb to release the
hard drive cover; remove the cover and lay aside for later reinstallation.
4.  Using finger pressure, slide the metal cover downwards toward the edge of the
notebook; then lift upwards to remove the metal cover.
5. Insert a small blade straight slot screwdriver into the recess in the plastics and
gently lift the frontmost edge of the drive out of the bay.
6. Lay the hard drive on its back.Then using a small straight slot screw driver, gently
pry on each end of the connector on the Disk Drive and rock it back and
forth until the connector is removed from the drive assembly. 
7.  Replacement is essentially the reverse of steps 1 through 6.
6.5.5   Removing/Replacing the Keyboard Assembly
The procedure for removing and replacing the keyboard assembly is as follows:  
1. Turn off the computer and disconnect the ac power adapter (if it is attached). 
2. The top edge of the keyboard is held in place by plastic tabs beneath the CTRL
and Right Arrow Keys. Pull the tabs toward the front of the notebook (tabs
snap into an 1/8 inch recess in the plastics).
3. Using a small straight-blade screwdriver, lift the front edge of the keyboard
upwards.
4. Lift the front edge of the keyboard slightly and gently pull the keyboard towards
the front of the notebook exposing two cables that connect the keyboard to
the main board. 
5. Release the two ZIF (zero insertion force ) connectors using a plastic stick or other
nonmetallic object and remove the cables from the main board connectors
6.Remove the keyboard assembly from the notebook. 
7.When installing the replacement keyboard, essentially reverse the above
procedures.
6.5.6  Removing/Replacing the Heat Sink
To remove and replace the heat sink, perform the following procedure:
1.  Remove the keyboard assembly as described in paragraph 6.5.5. 
2. Remove the two Phillips-head screws that secure the heatsink to the main board
(note that one of the screws is located near the HDD connector).
3. Lift upwards on the heatsink and remove it from the base.
4. Replacement is the reverse of steps 1 through 3 above.
 
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							6.5.7  Removing/Replacing Dual Inline Memory
Modules (DIMMS)
To remove and replace the expansion memory, use the following procedure:
1. Loosen the keyboard assembly (but do not disconnect keyboard cables) as
described in steps 1 through 5 of Paragraph 6.5.5).
2.
        Remove the Heatsink as described in Paragraph 6.5.6.
3. Using the back edge of the keyboard as a hinge, lift the front edge of the keyboard
up and lay it against the LCD assembly.
4. Push the two metal springs away from the board edge and remove the DIMMS
board. 
5. When installing a DIMMS board, insert the edge of the board into the rear of its
connector using a slight rocking motion at an angle to the surface of the
board.
6.  Once the DIMM is fully inserted in the connector, push downwards on both sides
of the board to snap it in place.
Figure 6-4  Removing/Replacing Expansion RAM
 
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							6.5.8   Removing and Replacing the Cover-Display
Assembly
To remove the cover -display assembly, perform the following procedure:
1.  Remove the keyboard and heatsink as described in paragraphs 6.5.5 and 6.5.6
respectively.
2.   Remove the cable cover below the display by lifting upwards on the front edge of
the cover.
4.   Unplug the video cable that mates with the Main Board.
5.  With the main video cable out of the way, two smaller cables are visible. Unplug
the rightmost cable.
6.  Using a plastic stick, slide the right and left hinge covers away from the base
assembly.
7. 
Lay the display completely back and remove the four screws that secure the
display hinges to the base case assembly.
8. 
Ensure that the display cables are free from the top case assembly and remove
the display assembly.
9.  Reinstallation of the Display Assembly is the reverse of steps 1 through 8 above.
6.5.9   Removing and Replacing the Inverter Board
To remove and replace the Inverter Board assembly, perform the following
procedure:
cCaution: If the notebook is powered up with the LCD bezel removed,
you can be exposed to high voltages which could result in shock and
equipment damage. Ensure that the batteries and AC adapter are re-
moved from the notebook when working on the LCD/Display assembly.
1. Use a narrow piece of plastic or pointed tweezers to apply light pressure to one
edge of the lower screw covers. The lower screw covers will bow outwards
and can be removed. 
2. Remove the rubber upper screw covers using a pair of tweezers.
3. Remove the six screws that secure the bezel to the display assembly (a small
Phillips-head screwdriver is recommended for removing the two screws at the
top of the bezel).
4. Pull on the inside edges of the bezel; remove bezel and lay aside for later
reinstallation.
5. Peel back the EMI shield along the right side of the display to expose the Inverter
Board.
6. Disconnect the connectors at the top and bottom of the Inverter Board.
7. Use the small Phillips-head screwdriver to remove the two screws holding the
Inverter Board; remove the Inverter Board Assembly.
 
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							8.  Reinstallation of the Inverter Board is the reverse of steps 1 through 7 above.
6.5.10  Opening/Replacing the Top Case Assembly
To remove/replace the Top Case Assembly, perform the following procedure:
1. Remove the Keyboard Assembly and Heat Sink Assembly as described in
Paragraphs 5.5.5 and 5.5.6.
2. Remove the four screws that secure the Top Case Assembly to the base. Note that
the screw at the rear of the opening is shorter than the remaining three
screws.
3. Using a plastic stick, unlock the ZIF connector located near the glide pad and
remove the cable from the connector. 
4.  Remove the cable cover below the display by lifting upwards on the front edge of
the cover.
5.  Turn the notebook over and remove the six Phillips-head screws from the bottom
of  the notebook.
6.  Rotate the notebook so that the rear of the unit is facing you; remove the rear
door assembly by bowing it outwards.
7. Several recesses are located just above the two rear connectors. Use a small
flat-blade screwdriver to disengage the snaps associated with the right and
left recesses.
8.  Lift and push the Display Assembly forward to disengage it from the Base
Assembly.
9.  Replacement of the Top Case Assembly is the reverse of steps 1 through 8 above.
6.5.11  Removing/Replacing the Touch Pad
Assembly
To remove and replace the Touch Pad Assembly, perform the following procedure:
1.  Remove the Top Case Assembly as described in the previous paragraph.
2. Turn the Top Case Assembly over and remove the four screws that secure a metal
shield to the plastics.
3. Lift the plastic frame that rests on top of the touch pad.
4. Unplug the flex cable from the connector on the touch pad. Note that the board
connector is a LIF (Low insertion force) type; the cable is held in place by
friction. 
5.  Slide the board assembly to the right and remove from the unit.
6. Replacement of the Touch Pad Board Assembly is essentially the reverse of Steps
1 through 5 above. 
 
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