Dell Inspiron Lm Service Guide

							Beep Codes and Error Messages 3-1
Chapter 3
Beep Codes and Error Messages
T
his chapter describes beep codes and system error messages that can occur 
during system start-up or, in the case of some failures, during normal computer 
operation. The tables in this chapter list faults that can cause a beep code or sys-
tem error message to occur and the probable causes of the fault in each case.
If a faulty computer does not emit beep codes or display system error messages 
to indicate a failure, you should load the diagnostics and run the appropriate 
tests to help isolate the source of the problem. See “Running the Dell Diagnos-
tics” found later in this chapter.
POST Beep Codes
If the display cannot display error messages during POST, the computer may 
emit a series of beeps that identify the problem or that can help you identify a 
faulty component or assembly. The following table lists the beep codes that may 
be generated during POST. Most beep codes indicate a fatal error that requires 
replacement of the main board or other corrective actions before the computer 
can operate. 
						

							3-2 Dell Latitude LM Systems Service Manual
     
Table 3-1.  POST Beep Codes 
Beep Code Error Probable Causes
1-2 Memory module not being 
properly identified or usedFault
y memory module or 
fault
y main board
1-2-2-3 ROM BIOS checksum failure Fault
y main board
1-3-1-1 DRAM refresh failure Fault
y main board
1-3-1-3 Ke
yboard controller test fail-
ureFaulty keyboard or faulty 
main board
1-3-4-1 RAM failure on address line 
nnnnFault
y memory module or 
fault
y main board
1-3-4-3 RAM failure on data bits 
nnnn 
of hi
gh byte on memory 
busFault
y memory module or 
fault
y main board
1-4-1-1 RAM failure on data bits 
nnnn 
of low b
yte on memory 
busFault
y memory module or 
fault
y main board
2-1-2-3 Check ROM co
pyright 
notice failureFaulty main board
2-2-3-1 Interru
pt mask register failure Faulty main board 
						

							Beep Codes and Error Messages 3-3
System Error Messages
The following table lists (in alphabetical order) system error messages that may 
appear on the display during the boot routine or during normal computer 
operation.
 
Table 3-2.  System Error Messages
Message Definition Probable Causes
Diskette drive A 
errorConnector loose or  dis-
kette faulty.Faulty or incorrectly 
inserted diskette in 
drive. Faulty diskette 
drive. Faulty main 
board.
Extended RAM 
failed at off-
set: 
nnnn
Extended memory not 
configured properly or 
failed at memory 
address nnnn.Faulty or improperly 
seated memory mod-
ule. Faulty main board.
Failing bits: 
nnnn Memory failed at RAM 
address nnnn.Faulty or improperly 
seated memory mod-
ule. Faulty main board.
Fixed disk 0 
failureHard-disk drive not 
responding to 
commands from com-
puter.Corrupted hard-disk 
drive boot sector or 
configuration file. 
Faulty hard-disk drive. 
Faulty main board.
Fixed disk con-
troller failureHard-disk drive or con-
troller not responding to 
commands from com-
puter.Faulty hard-disk drive. 
Faulty main board.
Incorrect drive 
A type—run SetupDiskette drive not iden-
tified properly in the 
Setup program. Incorrect drive 
configuration. Faulty 
connections. Faulty dis-
kette drive. Faulty 
main board.
Keyboard con-
troller errorKeyboard controller  
faulty.Faulty keyboard 
connection. Faulty key-
board. Faulty main 
board.  
						

							3-4 Dell Latitude LM Systems Service Manual
Keyboard errorKeyboard not respond-
ing correctly.Built-in keyboard: 
Faulty keyboard or key 
pressed while com-
puter booting. 
External keyboard: 
Cable or connector 
loose. Faulty keyboard 
or key pressed while 
computer booting.
Operating system 
not foundOperating system can-
not be found on hard-
disk drive or on diskette 
in diskette drive.Incorrect drive 
configuration. Operat-
ing system not installed 
on hard-disk drive or 
diskette drive not 
bootable. Faulty con-
nections. Faulty drive. 
Faulty main board.
Parity check 1 
nnnn
Parity error in system 
bus at address nnnn. Faulty main board.
Parity check 2 
nnnn
Parity error in I/O bus 
at address nnnn.Faulty main board.
Real time clock 
errorCMOS battery that 
supports data stored in 
NVRAM may be dead.Faulty battery. Faulty 
main board.
Shadow RAM 
failed at off-
set: 
nnnn
Shadow RAM failed at 
address nnnn.Faulty or improperly 
seated memory mod-
ule. Faulty main board.
System battery 
is dead—Replace 
and run SetupCMOS battery dead. Faulty CMOS battery 
or main board.
System cache 
error—cache 
disabledPrimary cache failed. Faulty microprocessor. 
Table 3-2.  System Error Messages (Continued)
Message Definition Probable Causes 
						

							Beep Codes and Error Messages 3-5
System CMOS 
checksum bad—run 
SetupCMOS has been cor-
rupted or modified, pos-
sibly by an application 
program that changes 
data stored in CMOS.BIOS has been updated.
System RAM 
failed at off-
set: 
nnnn
Memory not operating 
correctly. System RAM 
failed at address nnnn 
in the 64-KB block at 
which error was 
detected.Faulty or improperly 
seated memory mod-
ule. Faulty main board.
System timer 
errorTimer circuit on main 
board malfunctioning.Faulty main board.
Table 3-2.  System Error Messages (Continued)
Message Definition Probable Causes 
						

							3-6 Dell Latitude LM Systems Service Manual
Running the Dell Diagnostics        
The Dell diagnostics contains tests that aid in troubleshooting the computer.  
The diagnostics diskette contains the following test groups:
•RAM — Tests the main memory
•System Set — Tests the primary functions of the main board
•Video — Tests the video subsystem
•Keyboard — Tests the keyboard subsystem
•Mouse — Tests the mouse/touch pad subsystem
•Diskette Drives — Tests the diskette drive subsystem
•Hard-Disk Drives (Non-SCSI) — Tests the IDE hard-disk drive subsystem
•IDE CD ROM Drives — Tests a CD-ROM drive subsystem 
•Serial/Infrared Ports — Tests the serial communications port
•Parallel Ports — Tests the parallel communications port
•Audio — Tests the operation of the audio chip set
•SCSI Devices — Tests a SCSI hard-disk drive subsystem 
NOTE:  This test does not apply to Dell Latitude LM computers.
•Network Interface — Tests a network controller and its associated interface 
NOTE:  This test does not apply to Dell Latitude LM computers.
To start the diagnostics, turn off the computer, insert a diagnostics diskette into 
the diskette drive, and then turn on the computer.
Starting the diagnostics causes the Dell logo screen to appear, followed by a 
message indicating that the diagnostics is loading. Before the diagnostics loads, 
a program tests the portion of main memory (RAM) required for loading the 
diagnostics. If a main memory error is detected, a message appears on the 
screen telling you a memory module has failed.
If no errors are found in main memory, the diagnostics loads, and the Diagnos-
tics Menu appears. This menu lets you choose the following options or exit to 
the MS-DOS
® prompt:
•RUN QUICK TESTS — Runs preselected tests to quickly locate a computer 
failure or to indicate where further testing is needed to isolate a failure
•RUN ALL TESTS — Runs all tests for a thorough test of the computer
•RUN SPECIFIC TESTS — Tests a particular area or subsystem of the 
computer CAUTION:  To prevent damage to the original diagnostics diskette,
always use a backup copy of the 
diagnostics diskette 
when servicing a user’s
computer. Dell recommends that users make several copies of this diskette to
ensure that one is always available. 
						

							Removing and Replacing Parts 4-1
Chapter 4
Removing and Replacing Parts
T
his chapter provides procedures for removing and replacing components, 
assemblies, and subassemblies.  
Unless otherwise noted, each of the procedures in this chapter assumes the 
following:
•The computer and any attached peripherals are turned off and the peripher-
als disconnected from the computer’s I/O panel.
•A part can be replaced or installed by performing the removal procedure in 
reverse order.
When performing the procedures in this chapter that require the display assem-
bly to be open, use a book or something similar to support the display assembly. 
The angle of the display assembly with respect to the bottom case should not 
exceed 135 degrees. Also, assume that locations or directions relative to the 
computer are as shown in Figure 4-1 unless otherwise specified in a procedure.
Figure 4-1.  Computer Orientation
Recommended Tools 
Most of the procedures require the use of one or more of the following tools:
•Small flat-blade screwdriver
•Number 1 magnetized Phillips-head screwdriver
•Antistatic grounding strap
•Needle-nose pliers
right side
 left side back of computer
 front of computer 
						

							4-2 Dell Latitude LM Systems Service Manual
•Small scribe (or Delrin [plastic] screwdriver)
•Nut drivers
•Chip removal tool
Screw Identification and Tightening
.
Figure 4-2.  Screw Identification     
Where applicable, information about screw lengths is provided in illustrations. 
Before installing a screw, match the screw to the screw length graphics provided 
to check for correct length.CAUTION:  It is essential that the correct length screw be used when
reinstalling a screw. Otherwise, hardware damage could result. Make
sure that the screw is properly aligned with its corresponding hole, and
avoid overtightening.
B7
(screw B7 is 3 mm)
 3 mm 
						

							Removing and Replacing Parts 4-3
Precautionary Measures     
Before performing any of the procedures in this chapter, read the following 
warning.
1. Determine the power state of the computer.
If the display is on, go to step 2.
If the display is off, press any key on the keyboard to verify that the com-
puter is not in suspend or standby mode. Then proceed to step 2.
2. Turn off the computer and any attached peripherals.
3. Disconnect the computer and any attached peripherals from AC power 
sources to reduce the potential for personal injury or shock.
4. Remove the main battery from the battery compartment.
On the right side of the computer, press down on the battery cover until it 
unlocks and pull the battery straight out.
Figure 4-3.  Main Battery Removal
WARNING FOR YOUR PERSONAL SAFETY AND PROTECTION
OF THE EQUIPMENT: Before you start to work on the computer, per-
form the following steps in the sequence indicated.
1. Turn off the computer and any attached peripherals.
2. Disconnect the computer and any attached peripherals from AC
power sources to reduce the potential for personal injury or shock.
3. Ground yourself by attaching an antistatic grounding strap to your
wrist and to an unpainted metal surface on the computer’s I/O panel.
If an antistatic grounding strap is not available, periodically dis-
charge static electricity from your body by touching one of the
connectors on the I/O panel.
 cover 
						

							4-4 Dell Latitude LM Systems Service Manual
5. Remove the hard-disk drive assembly.
Turn the computer over and remove screws HD1 and HD2. Turn the com-
puter right side up. With the computer facing you, slide the hard-disk drive 
cover to the left and away from the computer. Using the handle on the front 
of the hard-disk drive, pull the drive straight out of the computer.
Figure 4-4.  Hard-Disk Drive Removal
6. Remove the diskette drive, secondary battery, or CD-ROM from the 
options drive bay.
NOTE:  The options bay allows the user to replace the lithium ion battery or 
diskette drive without turning off or rebooting the computer. This feature is 
sometimes called hot swapping. The CD-ROM can be inserted or removed 
while the computer is in suspend mode. This feature is sometimes called 
warm swapping. However, the CD-ROM must be in the computer before or 
during boot in order for the drivers to load.  
Turn the computer over and push the lock towards the options bay. Slide the 
latch toward the back of the computer (the latch does not move all the way 
to the lock groove).
  
Figure 4-5.  Options Bay Lock and Latch
cover
handle
HD1
HD2
(screws HD1 and HD2 are 10 mm)
10mm
lock
latch 
deviceback of the computer