HP Omnibook 4100 4150 Service Manual

HP OmniBook 4100/4150 Removal and Replacement 2-19
Removing the CPU Module
(HP Authorized Service Providers Only)
  Caution
 
For an OmniBook 4150 Series, do not unnecessarily remove the CPU module from the
motherboard. The CPU connector is easily damaged during removal and insertion.
  Table 2-8. CPU Component Compatibility
OmniBook 4100OmniBook 4150†
Pentium (T)266 MHzPentium II (MD)233-266 MHzPentium II (MD)300 MHz2-Screw Top Plate
Pentium II (MD,D)300-400 MHz5-Screw Top Plate
CPU moduleF1440-69102...

2-20 Removal and Replacement HP OmniBook 4100/4150
Removal Procedure
 1. Unplug the ac adapter, if present, and remove the battery.
 2. Remove these additional assemblies:
 · Floppy module or other module (page 2-3).
 · Hard disk drive (page 2-5).
 · Keyboard (page 2-9).
 3. For an OmniBook that has a 2-screw CPU top plate, remove the screw from the heatsink cover
and lift it off the heatpipe. (The figure on page 2-26 shows these and other parts.)
 4. Remove the screws holding the CPU top plate (see the...

HP OmniBook 4100/4150 Removal and Replacement 2-21
  Caution
 
In the next step, follow these precautions to prevent damage to the CPU connectors:
 ·  Do not raise the left end higher than the right end during removal.
 · OmniBook 4150B: Insert a flat, non-metallic blade under the front of the CPU module near
the right end. Pry up against the motherboard until the CPU releases. Repeat at the back
edge, then lift off the module.
 · OmniBook 4150†: Use the CPU removal tool to remove the CPU assembly.
  a....

2-22 Removal and Replacement HP OmniBook 4100/4150
Reassembly Notes
 · For an OmniBook 4100 or 4150†, before installing the CPU module, assemble it into the bottom
plate. For a 2-screw CPU top plate, attach the top plate to the assembly—do not attach a 5-screw
top plate before installing the assembly. Then install the assembly on the motherboard. See the
following caution.
  Caution
 
Install or replace CPU module thermal pads that are missing or damaged. Do not reuse a notched
CPU pad on a new CPU...

HP OmniBook 4100/4150 Removal and Replacement 2-23
 
Figure 2-11. Positioning Thermal Pads
CPU, 333-400 Pentium II (D)
(1 thermal pad
on bottom of top plate)
CPU, 233-300 Pentium II (MD)
(2 thermal pads) CPU, Pentium (T)
(4 thermal pads)
Note: Spacer
(OmniBook 4100
only)
CPU, 300 Pentium II (MD)
(1 thermal pad
on bottom of top plate)
OmniBook 4100/4150†, 2-Screw Top Plate
OmniBook 4150†, 5-Screw Top PlateInstall new pad on new CPU
CPU, 366-400 Pentium II (D)
(1 thermal pad
on bottom of heatsink/top...

2-24 Removal and Replacement HP OmniBook 4100/4150
Removing the Motherboard or Bottom Case
(HP Authorized Service Providers Only)
Required Equipment
 · Small Phillips screwdriver.
 · 5-mm hex driver (or 3/16 inch).
 · OmniBook 4150 CPU removal tool (HP part number T-335665).
Removal Procedure
 1. Unplug the ac adapter, if present, and remove the battery.
 2. Remove these additional assemblies:
 · Floppy module or other module (page 2-3).
 · Hard disk drive (page 2-5).
 · Keyboard (page 2-9).
 · Display...

HP OmniBook 4100/4150 Removal and Replacement 2-25
 7. Unplug the fan cable from the motherboard.
 8. On the left frame, remove the screw that holds the plastic heat exchange cover. On an OmniBook
4150B, remove the second screw from the fan. Lift off the cover and fan – they are a single
assembly on the OmniBook 4150B.
 9. On the left frame, remove the screw that holds the frame to the motherboard, then lift out the
frame.
 10. Lift out the side air vent cover. If a finned heatsink is present at the left...

2-26 Removal and Replacement HP OmniBook 4100/4150
 
 Figure 2-12. Removing the Motherboard
Screw, M2×14mm (2)*Screw, M2×3.5mm or*
M3×4mm
CPU with top plate, bottom plate*
LVDS PCA
VGA PCAHeatsink cover*
Heatsink (finned)*
DC-DC PCA
Audio jack PCA
VGA standoff (2)
Air vent cover
Left frame
Screw, M2.5×5mm
IR PCA
Audio jack cover
Right frame
Screw, M2.5×5mm
RAM/BIOS
cover
Screw, M2×3.5mm
(OB 4100) or
M3×4mm
(OB 4150)
Heatpipe*
(part of CPU top plate)
Heat exchange cover
(For OB 4150B this is part
of fan,...

HP OmniBook 4100/4150 Removal and Replacement 2-27
Reassembly Notes
  Note: Installing a New Motherboard
 · Caution: Replace the motherboard with one that is compatible with the OmniBook model and
CPU module—see the table on page 2-19.
 ·  If any RAM boards are present, transfer them from the old motherboard to the new one:
 ·  Reprogram the BIOS IC—see the note below.
 ·  Store the serial number electronically in the new motherboard—see the steps below.
 
Note: Installing a New Bottom Case
 ·  Transfer...

2-28 Removal and Replacement HP OmniBook 4100/4150
 
                        
 Figure 2-13. Installing Docking Doors and Module Latch
Storing the Serial Number Electronically
 1. Exit Windows and boot to a DOS prompt.
 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 4100 or 4150
Recovery CD, then run it on the OmniBook.
 3....