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...

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...

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 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...

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...

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...

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...

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...

2-30 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.