Dell Inspiron L400 Service Guide

							support.dell.com Dell Latitude L400 Service Manual 27
Speaker
Figure 21.  Speaker Removal 
1. Remove the keyboard bezel.
2. Remove the display assembly.
3. Remove the keyboard assembly.
4. Remove the palmrest assembly.
NOTICE: To ensure maximum cooling for the microprocessor, do not 
touch the glue side of the thermal conductive tape. The oils in your 
skin reduce the heat transfer capability on the glue side of the tape. 
5. Peel up the EMI adhesive sponge that connects the audio EMI shield to 
the thermal cooling solution (see Figure 21).
You only need to peel up the part of the sponge that lies on the thermal 
cooling solution. The end of the sponge that lies on the audio EMI shield 
can remain.
audio EMI 
shield
EMI adhesive sponge
speaker with 
rubber gasket
speaker wire
connector
M2 x 5-mm screws 
(2) with rubber 
washers 
						

							28 Dell Latitude L400 Service Manual
NOTICE: The audio EMI shield is attached to the USB connector   
housing with two-sided tape. To avoid bending the audio EMI shield, 
care must be taken when separating the audio EMI shield from the 
USB connector housing.
6. Using a small flat-blade screwdriver, carefully separate the audio EMI 
shield away from the USB connector housing.
Place the edge of the screwdriver between the audio EMI shield and the 
USB connector housing, and slowly pry the two apart.
7. Carefully disconnect the speaker wire connector from the system board.
The male connector on the speaker wire is keyed to fit into the female 
connector one way only.
8. Remove the two M2 x 5-mm screws with rubber washers that secure the 
speaker to the bottom assembly.
9. Remove the speaker from the bottom assembly.
10. Remove the rubber speaker gasket from the bottom assembly.
To replace the speaker, perform the following steps:
1. Reinstall the rubber speaker gasket in the bottom case.
The gasket is keyed, so it will fit in the bottom case one way only. 
2. Place the speaker in the bottom case.
3. The wire end of the speaker should face towards the center of the bottom 
assembly.
4. Reinstall the two M2 x 5-mm screws with rubber washers to secure the 
speaker to the bottom assembly.
5. Carefully connect the speaker wire to the connector in the system board 
assembly. 
The male connector on the speaker wire is keyed to fit into the female 
connector one way only.
6. Reinstall the audio EMI shield.
a. Carefully position the audio EMI shield so the section with the         
two-sided tape is over the USB connector housing. 
b. Press the audio EMI shield down so it attaches to the USB connector 
housing. 
c. Reattach the EMI adhesive sponge across the thermal cooling solution. 
						

							support.dell.com Dell Latitude L400 Service Manual 29
7. Reinstall the palmrest assembly.
8. Reinstall the keyboard assembly.
9. Reinstall the display assembly.
10. Reinstall the keyboard bezel.
System Board Assembly 
6
Figure 22.  System Board Assembly Removal 
To remove the system board assembly, perform the following steps.
NOTICE: If the EMI sponge located between the battery bay and the 
USB connector becomes dislodged, reinsert it.
PC Card cover
system board
fan assembly
M2 x 9.5-mm screw
audio I/O port cover audio EMI 
shield
fan wire connector
M2 x 4-mm 
screws (2)
thermal 
cooling solution
M2 x 3.5-mm 
screws (6)
modem retainer bracket
modem
reser ve batter y
bottom case 
assembly EMI clip 
location
EMI adhesive sponge
speaker
USB connector 
						

							30 Dell Latitude L400 Service Manual
NOTICE: To avoid damaging the system board, you must remove the 
main battery before you service the computer.
NOTICE: The processor is not replaceable. Do not attempt to remove 
the thermal cooling solution.
1. Remove the keyboard bezel.
2. Remove the display assembly.
3. Remove the keyboard.
4. Remove the palmrest assembly.
5. Use a 5-mm socket wrench to remove the four 5-mm socket screws for the 
VGA and parallel ports located on the back of the bottom case assembly.
6. Use a small flat-blade screwdriver to remove the two IDE connector 
screws at both ends of the IDE (modular bay) connector located on the 
back of the bottom case assembly.
NOTICE: To ensure maximum cooling for the microprocessor, do not 
touch the glue side of the thermal conductive tape. The oils in your 
skin reduce the heat transfer capability on the glue side of the tape. 
7. Peel up the EMI adhesive sponge that connects the audio EMI shield to 
the thermal cooling solution (see Figure 22).
You only need to peel up the part of the sponge that lays on the thermal 
cooling solution. The end of the sponge that lays on the audio EMI shield 
can remain.
NOTICE: The audio EMI shield is attached to the USB connector    
housing with two-sided tape. To avoid bending the audio EMI shield, 
care must be taken when separating the audio EMI shield from the 
USB connector housing.
8. Using a small flat-blade screwdriver, carefully separate the audio EMI 
shield away from the USB connector housing.
Place the edge of the screwdriver between the audio EMI shield and the 
USB connector housing, and slowly pry the two apart.
9. Remove the two M2 x 4-mm screws that secure the audio I/O cover to the 
bottom case assembly.
10. Remove the audio I/O cover.
11. Remove the six M2 x 3.5-mm screws that secure the system board to the 
bottom case assembly.
White arrows on the system board assembly point to the  
M2 x 3.5-mm screws.
12. Remove the M2 x 9.5-mm screw that secures the modem retainer bracket. 
						

							support.dell.com Dell Latitude L400 Service Manual 31
13. Remove the modem retainer bracket from the bottom case assembly.
14. Disconnect the speaker wire from the connector on the system board 
assembly.
15. Disconnect the fan wire from the connector on the system board 
assembly.
16. Lift the system board assembly out of the bottom case assembly.
To replace the system board assembly, perform the following steps:
1. Transfer the memory module(s) to the replacement system board 
assembly.
2. Place the new hard-disk drive EMI clip on the system board assembly     
(see Figure 23).
Figure 23.  Hard-Disk Drive EMI Clip
3. Place the system board assembly in the bottom case assembly.
The I/O ports should protrude comfortably through the openings at the 
back of the bottom case assembly.
4. Reconnect the fan wire to the connector on the system board assembly.
5. Reconnect the speaker wire to the connector on the system board 
assembly.
6. Replace the modem retainer bracket around the I/O ports and on top of the 
modem.
7. Reinstall the M2 x 9.5-mm screw on the right side of the modem to secure 
the modem retainer bracket to the system board assembly. 
The hole for the M2 x 9.5-mm screw is located by the VGA port.
8. Reinstall the six M2 x 3.5-mm screws that secure the system board 
assembly to the bottom case assembly.
White arrows on the system board assembly point to the screw holes.
hard-disk drive 
EMI clip
M2 x 3.5-mm screw 
						

							32 Dell Latitude L400 Service Manual
One of the M2 x 3.5-mm screws passes through the hard-disk drive EMI 
clip (see Figure 23).
9. Reinstall the audio EMI shield.
a. Carefully position the audio EMI shield so the section with the         
two-sided tape is over the USB connector housing. 
b. Press the audio EMI shield down so it attaches to the USB connector 
housing. 
c. Reattach the EMI adhesive sponge across the thermal cooling solution.
10. Reinstall the two IDE connector screws at both ends of the IDE (modular 
bay) connector located on the back of the bottom case assembly.
11. Reinstall the four 5-mm socket screws for the VGA and parallel ports 
located on the back of the bottom case assembly.
12. Replace the audio I/O cover.
13. Replace the two M2 x 4-mm screws to secure the audio I/O cover to the 
bottom case assembly.
14. Reinstall the palmrest assembly.
15. Reinstall the keyboard assembly.
16. Reinstall the display assembly.
17. Reinstall the keyboard bezel.
Main Battery Release Latch
 
Figure 24.  Main Battery Release Latch Removal
main batter y release latch
tension spring
release button
bottom case assembly 
						

							support.dell.com Dell Latitude L400 Service Manual 33
1. Remove the keyboard bezel.
2. Remove the display assembly.
3. Remove the keyboard.
4. Remove the palmrest assembly.
5. Remove the system board.
NOTICE: The tabs on the release button are plastic. Care should be 
taken when squeezing the tabs to avoid breaking them.
6. Using needle-nose pliers, gently squeeze the two tabs on the back of the 
release button together and grasp the top of the battery release latch and 
gently pull up to free it from the release button assembly (see Figure 24).
7. To remove the battery release latch, unhook the small tension spring 
located on the metal post next to the hard-disk drive.
APR Docking Doors
1. Turn the computer upside down.
The APR docking doors should be at the top.
2. Carefully insert a small flat-blade screwdriver in the opening between the 
door edges and the edge of the door opening on the right side.
There is a small slot at the right edge of the door opening to show where 
the screwdriver is placed.
3. Gently push the screw driver against the right edge of the back door to 
cause the door to bow up at their center. 
4. Grasp the back door as it bows up while still pressing the door edge with 
the screwdriver.
5. Carefully slip the right-edge hinge of the back door off its right hinge pin.
NOTICE: The doors are attached to each other by a tension spring at 
the left end of the doors. Do not try to separate the doors from each 
other.  They must be removed together.  
6. Gently push the screw driver against the right edge of the front door to 
cause the door to bow up at their center. 
7. Grasp the front door as it bows up while still pressing the door edge with 
the screwdriver.
8. Carefully slip the right-edge hinge of the front door off its right hinge pin. 
9. Grasping both doors together, carefully slip the left side of each door off 
their left hinge pins.  
						

							34 Dell Latitude L400 Service Manual
To replace the APR docking doors, perform the following steps.
NOTE: On the under side of the doors, a small F is printed on the front door 
and a small B is printed on the back door. As you hold the doors for installation, 
the front door is near you, the back door is away from you, and the tension 
spring is to the left.
1. Turn the computer upside down.
The APR connector door opening should be at the top.
2. Holding the two doors together at their right edges, insert the left hinges 
of the doors (at the end with the tension spring) onto the left, front and 
back hinge pins.
3. Carefully bow the doors in the center.
4. Slip the right hinge of the back door on to the right, back hinge pin.
5. Slip the right hinge of the front door on to the right, front hinge pin.
6. Release the doors so they set into place. 
						

							Index 1
Index
A
APR docking doors removal, 33
B
bottom assembly
components, 
22
illustrated, 22
D
display assembly
bezel removal, 
11
hinge removal, 15
latch removal, 12
removal, 9
F
fan removal, 25
field-replaceable parts and 
assemblies illustrated, 
6
G
grounding to dissipate static 
electricity, 
3
H
hard-disk drive assembly removal, 7
hinge removal, 15
K
keyboard assembly removal, 16
L
latch removal, 12
LCD panel removal, 13
M
main battery
release latch removal, 
32
removal, 3, 23
memory module removal, 18
modem removal, 24
P
palmrest assembly removal, 19 
						

							2 Dell Latitude L400 Service Manual
R
reserve battery removal, 23
S
screw identification and tightening, 3
speaker removal, 27
system board assembly
removal, 
29
T
tools, 2
touch pad removal, 21
Z
ZIF connectors, 5