HP Omnibook 900 Service Manual

							HP OmniBook 900 Removal and Replacement 2-21
 10. Lift the front of the motherboard about 7 cm (3 inches), then slide the motherboard forward until
it comes out of the bottom case.
 
 
 Figure 2-11. Removing the Motherboard
PCMCIA socket
Motherboard
Speaker cable
Speaker
Bottom case
CPU support
(OB 900B only)
Infrared lens
Fan cable
Fan
Hard drive door
Screw, M2.5×8mm
Right hinge support
Screw, M2.5×4mm
Screw, M2.5×4mm
Mylar insulator
Standoff, M2 
						

							2-22 Removal and Replacement HP OmniBook 900
Reassembly Notes
  Note: Installing a New Motherboard
 ·  If a RAM board is present, transfer it from the old motherboard to the new one:
 · Reprogram the BIOS IC—see the note below.
 ·  Store the serial number and keyboard layout electronically in the new motherboard—see the
steps below.
 
Note: Installing a New Bottom Case
 ·  Transfer these parts from the old bottom case to the new one:
 
HDD door and infrared lens.
 
Module bay door. (If the door does not stick to the case, the motherboard will hold it.)
 
PCMCIA doors, if present (see the figure below).
 
Speaker. (If the covering is not reusable, install a new speaker.)
 
Fan. (Do not press or spin the fan blade with your finger.)
 
Mylar insulator (inside the bottom case).
 
CPU support (OmniBook 900B only).
 ·  Install the original serial number label and a new overlay—see the steps below if you have to
make a new serial number label.
 · When lowering the motherboard into the bottom case, make sure the audio jack grounding tabs do
not catch on the bottom case.
 · Make sure the speaker and fan wires are not trapped under the motherboard.
 
Note
 
If you installed a new motherboard with a new BIOS IC, the IC contains only enough basic
programming to boot the OmniBook. After installing the motherboard, you must reprogram the IC.
Hewlett-Packard prefers that you program the IC with the latest BIOS. You can download it from
the OmniBook website (see page vi)—follow the directions provided.
 
Note
 
For an OmniBook 900 with a 12-inch display and serial number before TW 92500000, if you must
replace the motherboard or bottom case, check whether you must replace additional parts:
 ·  If the bottom case has a large blue pad that covers the bottom of the hard disk slot, replace
just the bad part.
 ·  If the bottom case does not have such a pad in the hard disk slot, it is an old bottom case,
and you should replace the top case, bottom case, and install a HDD bracket above the hard
disk slot. (Service note 900-14.) 
						

							HP OmniBook 900 Removal and Replacement 2-23
 
 
  Figure 2-12. Installing PCMCIA Doors
Storing the Serial Number and Keyboard Layout Electronically
 1. Exit Windows and boot to a DOS prompt.
  For Windows 95/98, press F8 during reboot and select Command Prompt Only.
  For Windows NT, boot from a DOS boot floppy disk.
 2. Run ESN.EXE from one of these sources:
  On a factory software installation, change to the \Omnibook\Drivers\Hputils directory and
type 
esn at the prompt.
  Otherwise, copy \Omnibook\Drivers\Hputils\Esn.exe from the OmniBook 900 Recovery CD,
then run it on the OmniBook.
 3. Store the serial number:
  If you are prompted for the serial number, type the serial number shown on the bottom of the
case.
  If a serial number has already been stored, you must call an HP support center to change it.
 4. Run KYB_SEL.EXE from one of these sources:
  It may be present on the hard disk or Recovery CD in \OmniBook\Drivers\Hputils.
  Get a copy from the Reseller website (see page vi).
 5. Select the keyboard layout for the unit being repaired.
Installing a New Serial Number Label
If you do not have a master file that creates serial number labels with fields for “900 B” and
manufacturing location, get a copy from the Reseller website (see page vi) under Product Support
Information in the Service and Support Library.
 1. Using any PC connected to a laser printer, open the master serial label file, enter the serial number
and product number from the old serial label, and print the new label on plain white paper. The
new label does not have barcodes.
Note: View from inside the
case. Rotate the doors 180°
to load the spring. 
						

							2-24 Removal and Replacement HP OmniBook 900
 2. Carefully cut out the new serial label just inside the border and place it into the inner recess in the
bottom case. The bottom of the label goes toward the front of the case.
 3. While holding the paper label in place, attach a serial label overlay into the outer recess. It covers
and protects the serial label.
HP Serial Number (S)TW711A1234 900 B
(1P)F1770W MFG# TW711A1234
Made in Taiwan
  Figure 2-13. Example of Serial Number Label
Removing the BIOS IC
(HP Authorized Service Providers Only)
  Note
 
A replacement BIOS IC contains only enough basic programming to boot the OmniBook. After
installing the IC, you must reprogram it. Hewlett-Packard prefers that you program the IC with the
latest BIOS. You can download it from the OmniBook website (see page vi)—follow the directions
provided.
Required Equipment
 · Small Phillips screwdriver.
 · IC (PLCC) removal tool (similar to OK Industries EX-5).
Removal Procedure
 
Caution
 
Remove all power before removing or installing the BIOS IC. Otherwise, the IC could be damaged.
 1. Unplug the ac adapter, if present, and remove the battery.
 2. Put your finger above the F8 key and slide the keyboard-screw cover to the left about 3 mm
(1/8 inch)—then lift off the cover.
 3. Remove the two screws holding the keyboard above the F1 and HOME keys. If your screwdriver
has a fat shaft, protect or remove the right hinge cover.
 4. Lift up the keyboard tab above the F1 key about 10 mm (1/2 inch), then free the snap at the center
of the back edge.
 5. Slide the keyboard toward the display about 5 mm (1/4 inch), then fold the keyboard forward onto
the front of the top case.
  Warning
 
Do not touch the heatsink until it has cooled. It could be hot if the computer was running recently.
 6. Use an IC removal tool to remove the BIOS IC from its socket. 
						

							HP OmniBook 900 Removal and Replacement 2-25
 
 Figure 2-14. Removing the BIOS IC
Reassembly Notes
  Caution
 ·  Align the IC with the slot in the socket. The IC is keyed to fit correctly. If you insert the IC
backward, the IC or motherboard could be damaged.
 · Press down firmly on the IC with your thumb to ensure a proper connection.
 · Fold the keyboard back into place. Slip its front tabs into the slots, then snap the back edge into
place.
 · Push the keyboard toward the back as you tighten the two screws. This helps engage the tab at the
back-center of the keyboard.
 · Reprogram the IC by programming the BIOS—see the note above.
IC removal tool 
						

							2-26 Removal and Replacement HP OmniBook 900
Removing Other Components
(HP Authorized Service Providers Only)
Required Equipment
 · Small Phillips screwdriver.
 · Pointed knife or probe (for display components).
 · Small flat-blade screwdriver (for display components).
 · 4.0-4.5 mm flat-blade screwdriver (for OmniBook 900B CPU only).
 · Fine Phillips screwdriver (for display latch only).
 · 4-mm thin-wall hex driver (or 5/32 inch) (for bottom case components).
 · Small plastic blade for prying, such as an angled plastic tweezers (for bottom case components).
Removal Procedure
 1. Unplug the ac adapter, if present, and remove the battery.
 2. Remove the additional assemblies and follow the special steps indicated in the tables below.
Components are separated into these groups:
 · Display components (page 2-27).
 · Top case components (page 2-28).
 · Bottom case components (page 2-28). 
						

							HP OmniBook 900 Removal and Replacement 2-27
 Table 2-8. Removing Display Components
ComponentRemoval ProceduresAdditional Steps (See figure on page 4-6)
Bezel, displayRemove the display bezel (see page 2-10).
Cable, display flex
(12-inch display)Keyboard (page 2-12).
Display (page 2-16).
LCD module (page 2-10).1.  Unsnap the flex cable tube from the display case.
2. Remove the screw holding the left hinge arm and
release the flex cable grounding strap.
Reassembly Notes: The grounding strap goes
between the left hinge arm and the display case. It is
held by the hinge screw.
The flex cable wraps around the tube only about 1/2
turn.
Cable, display flex
 (13-inch display)Keyboard (page 2-12). 1. Remove the left hinge cover.
2. Remove the bezel and display case (see page 2-
10).
3. Disconnect the flex cable from the LCD.
4. Unplug the flex cable from the motherboard.
Cable, display powerKeyboard (page 2-12). 1. Remove the right hinge cover.
2. Remove the display bezel (see page 2-10).
3. Unplug the power cable from the LCD module
wires.
4. Unplug the power cable from the motherboard.
Reassembly Notes: Insert the display power cable
into the notch in the top case before installing the
hinge cover.
Case, display
(12-inch display)Keyboard (page 2-12).
Display (page 2-16).
LCD module (page 2-10).1. Remove the screws holding the hinge arms, then lift
out the hinges.
2. Unsnap the flex cable tube from the display case.
Lift out the flex cable.
3. Remove the two screws holding the display latch,
then lift out the latch.
Reassembly Notes: Install the display latch and other
components into the new display case.
Case, display
(13-inch display)Keyboard (page 2-12). 1. Remove the bezel and display case (see page 2-
10).
2. Remove the two screws holding the display latch,
then lift out the latch.
Reassembly Notes: Install the display latch and other
components into the new display case.
HingeKeyboard (page 2-12).
Display (page 2-16).1. Remove the display bezel (see page 2-10).
2. 12-inch display: Remove the screw holding the
hinge arm, then lift out the hinge.
13-inch display: Remove the two screws securing
the hinge arm to the LCD module.
Reassembly Notes (12-inch display): Insert the
hinge fully into the case before installing the screw.
Latch, display1. Remove the display bezel (see page 2-10).
2. Remove the two screws holding the latch, then lift
out the latch.
LCD moduleSee page 2-10. 
						

							2-28 Removal and Replacement HP OmniBook 900
 Table 2-9. Removing Top Case Components
ComponentRemoval ProceduresAdditional Steps (See figure on page 4-2)
Case, topSee page 2-18.
KeyboardSee page 2-12.
Support, touch-padHard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).1. Remove the screw holding the support plate to the
top case.
2. Slide the support plate to the side and lift it out.
Reassembly Notes: Make sure the touch pad is
seated properly before installing the support plate.
Press down on the support plate while sliding it into
place. Make sure it is held down at the left and right
edges.
Check the action of the click buttons before installing
the top case.
Touch padHard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).1. Remove the screw holding the support plate to the
top case.
2. Slide the support plate to the side and lift it out.
3. Lift out the touch pad and its flex cable.
Reassembly Notes: Make sure the touch pad is
seated properly before installing the support plate.
Press down on the support plate while sliding it into
place. Make sure it is held down at the left and right
edges.
Check the action of the click buttons before installing
the top case.
 Table 2-10. Removing Bottom Case Components
ComponentRemoval ProceduresAdditional Steps (See figure on page 4-2)
Case, bottomSee page 2-20.
CPU moduleSee page 2-14.
Door, module bay
connectorHard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
CPU (page 2-14).
Top case (page 2-18).
Motherboard (page 2-20).Peel the rubber door from the bottom case.
Reassembly Notes: Position the new door in the
center of the opening before sticking it onto the bottom
case.
Doors, PCMCIAHard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).Flex each door until one side tab releases.
Reassembly Notes: See the figure on page 2-23.
Fan
(12-inch display)Keyboard (page 2-12).
Fan
(13-inch display)Hard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).Caution: Do not spin the fan blade with your finger.
Pressure on the fan blade can damage the bearings.
1.Remove the eight screws (OmniBook 900†) or six
screws and two springs (OmniBook 900B) from the
heatsink and lift off the heatsink.
2. Remove the two screws (12-inch display) or one
screw (13-inch display) holding the fan.
3. Unplug the fan cable from the motherboard and lift
out the fan.
Reassembly Notes: The opening in the side of the fan
faces the vent in the bottom case. 
						

							HP OmniBook 900 Removal and Replacement 2-29
ComponentRemoval ProceduresAdditional Steps (See figure on page 4-2)
HeatsinkKeyboard (page 2-12).Remove the eight screws (OmniBook 900†) or six
screws and two springs (OmniBook 900B) from the
heatsink and lift off the heatsink.
Reassembly Notes: Install new thermal pads on the
new heatsink.
IC, BIOSSee page 2-23.
Insulator, bottom caseHard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
CPU (page 2-14).
Top case (page 2-18).
Motherboard (page 2-20).Lift the sheet out of the bottom case.
Reassembly Notes: The small pads on the sheet face
upwards.
Lens, infraredHard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).Slide the infrared lens out of the bottom case.
Pads, thermalKeyboard (page 2-12). 1. Remove the eight screws (OmniBook 900†) or six
screws and two springs (OmniBook 900B) from the
heatsink and lift off the heatsink.
2. Install or replace damaged or missing thermal pads
on the bottom of the heatsink.
3. Clean off the mating surfaces of the CPU module
and the large IC next to it.
Reassembly Notes: Install the smaller pad in the
recessed area of the same shape.
Install the larger pad in the middle of the protruding
area.
PCA, motherboardSee page 2-20.
Socket, PCMCIAKeyboard (page 2-12). 1. Remove the eight screws (OmniBook 900†) or six
screws and two springs (OmniBook 900B) from the
heatsink and lift off the heatsink.
2. Remove the two screws from the right side of the
PCMCIA socket.
3. Unplug the PCMCIA socket flex cable from the
motherboard and slide out the socket.
Speaker
(12-inch display)Hard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).1. Unplug the speaker from the motherboard.
2. Peel off the covering from the speaker chamber.
3. Pull the speaker out of the bottom case.
Reassembly Notes: Make sure the foam pads are
attached to the edges and back of the speaker.
After inserting the speaker, carefully seal the speaker
chamber with the new covering material.
Speaker
(13-inch display)Hard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
CPU (page 2-14).
Top case (page 2-18).
Motherboard (page 2-20).Pull the speaker out of the bottom case.
Support, hinge (left)Hard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).Unsnap the left hinge support from the top case. 
						

							2-30 Removal and Replacement HP OmniBook 900
ComponentRemoval ProceduresAdditional Steps (See figure on page 4-2)
Support, hinge (right)Hard drive (page 2-6).
Keyboard (page 2-12).
Display (page 2-16).
Top case (page 2-18).Remove the screw holding the right hinge support near
the back-right corner, then lift out the support.