Acer Travelmate 4720 Service Guide

							Chapter 491
Use the following procedure as a guide for computer problems.
NOTE: The diagnostic tests are intended to test only Acer products. Non-Acer products, prototype cards, or 
modified options can give false errors and invalid system responses.
1.Obtain the failing symptoms in as much detail as possible.
2.Verify the symptoms by attempting to recreate the failure by running the diagnostic tests or repeating the 
same operation.
3.Do not use any power sources when performing an assembly or disassembly procedures.
4.If any problems occur, you can perform the following visual inspection before you continue. 
TPower cords are properly connected and secured.
TThere are no obvious shorts or opens.
TThere are no burned or heated components.
TAll components appear normal.
Troubleshooting
Chapter 4 
						

							92Chapter 4
System Check Procedures
External CD/DVD-ROM Drive Check
Perform the following procedures to isolate the possible problem a controller, drive, or CD-ROM. 
NOTE: Make sure that the CD-ROM does not have any label attached to it. The label may damage the drive or 
cause drive failure.
1.Boot from the diagnostic disc and start the diagnostic programs.
2.See if CD-ROM Test is passed when the program runs the CD-ROM Test.
3.Follow onscreen instructions.
If an error occurs, reconnect the drive to the connector on the mainboard. If the error persists, do the following:
1.Reconnect the CD/DVD-ROM drive.
2.Replace the CD/DVD-ROM drive.
3.Replace the mainboard.
Keyboard or Auxiliary Input Device Check
Remove the external keyboard if the internal keyboard is to be tested.
If the internal keyboard does not work or an unexpected error occurs, make sure that the flexible cable 
extending from the internal keyboard is correctly connected to the mainboard. If the keyboard cable 
connection is correct, run the Keyboard Test. 
If the tests detect a keyboard problem, do the following procedures in sequence to correct the problems. Do 
not replace a non-defective FRU:
1.Reconnect the keyboard cable.
2.Replace the keyboard.
3.Replace the mainboard.
The following auxiliary input devices are supported by this computer:
TNumeric keypad
TExternal keyboard
If any of these devices do not function, reconnect the cable and repeat above procedures. 
Memory Check
NOTE: Make sure that the DIMM is properly installed into the connector. A loose connection can cause an 
error.
Do the following:
1.Boot from the diagnostic diskette and start the diagnostic program.
2.Go to the diagnostic memory in the test items.
3.Press F2 in the test items.
4.Follow onscreen instructions. 
						

							Chapter 493
Power System Check
Do the following:
1.Remove the battery pack.
2.Connect the power adapter and check the power supply.
3.Disconnect the power adapter and install the battery pack; then check that power supply.
If you suspect a power problem, see the appropriate power supply check in the following list:
T“Check the Power Adapter” on page 93
T“Check the Battery Pack” on page 93
Check the Power Adapter
Unplug the power adapter cable from the system and measure the output voltage at the plug of the power 
adapter cable. 
1.If the voltage is not correct, replace the power adapter.
2.If the voltage is within range, do the following:
a.Replace the System board.
b.If the problem is not resolved, see “Undetermined Problems” on page 107.
c.If the voltage is not correct, go to the next step.
NOTE: An audible noise from the power adapter does not always indicate a defect.
3.If the power-on indicator does not light up, check if the adapter’s power cord is properly connected to the 
system.
4.If the operational charge does not work, see “Check the Battery Pack” on page 93. 
Check the Battery Pack 
Do the following:
Using the software to identify whether a problem occurs while the battery pack during recharge or discharge:
1.Open Power Management in the Control Panel.
2.In Power Meter, confirm if the parameters for Current Power Source and Total Battery Power Remaining 
are correct.
3.Repeat the steps 1 and 2 for both battery and adapter.
Using the hardware to identify whether you should replace the battery pack or not:
1.Power off the system. 
2.Remove the battery pack and measure the voltage between terminals one (+) and seven (-). There are 
seven terminals totally. 
3.If the voltage is still less than 7.5 Vdc after recharging, replace the battery. 
If the battery status indicator does not light up, remove the battery pack . If the charge indicator still does not 
light up, replace the AC/DC charger board.   
						

							94Chapter 4
Touchpad Check
If the touchpad doesn’t work, do the following  procedures in sequence to correct the problem. Do not replace 
a non-defective FRU:
1.After rebooting, run Tracking Pad PS2 Mode Driver. For example Syn touch driver.
2.Run utility with the PS/2 mouse function and check if the mouse is working.
3.If the PS/2 mouse does not work, then click if the main board to switch board FPC is connected properly.
4.If the main board to switch board FPC is connected correctly, then check if the FFC on the touch pad PCB 
is connected properly.
5.If the FFC on the touch pad PCB is connected correctly, check if LS851 JP1 Pin6 = 5V are pules. If yes, 
then replace switch board. If not, then go to the next step.
6.Replace the touch pad PCB.
7.If the touch pad still does not work, then replace the FPC on Track Pad PCB.
After you use the touchpad, the pointer drifts on the screen for a short time. This self-acting pointer movement 
will occur when a slight, steady pressure is applied to the touchpad pointer. This symptom is not a hardware 
problem. No actions are necessary to be taken if the pointer movement stops in a short period of time. 
						

							Chapter 495
Power-On Self-Test (POST) Error Message 
The POST error message index lists the error message and their possible causes. 
NOTE: Perform the FRU replacement or actions in the sequence shown in FRU/Action column, if the FRU 
replacement does not solve the problem, put the original part back in the computer. Do not replace a 
non-defective FRU.
The error messages are listed in the coming pages to indicate the BIOS signals on the screen and the error 
symptoms classified by functions. If the symptom is not included on the list, please refer to “Undetermined 
Problems”. 
NOTE: Most of the error messages occur during POST. Some of them display information about a hardware 
device, e.g., the amount of memory installed. Others may indicate a problem with a device, such as the 
way it has been configured. 
NOTE: If the system fails after you make changes in the BIOS Setup Utility menus, reset the computer, enter 
Setup and install Setup defaults or correct the error.  
						

							96Chapter 4
Index of Error Messages
Error Message List
Error MessagesCheck or do the following in sequence:
Stuck Key See “Keyboard or Auxiliary Input Device Check” on page 92. 
System CMOS checksum bad - Default 
configuration used
TRTC battery.
TRun the BIOS Setup Utility to reconfigure the system time, 
then reboot system.
Real time clock error
TRTC battery
TRun the BIOS Setup Utility to reconfigure system time, then 
reboot system.
TMainboard
Previous boot incomplete - Default 
configuration used
TRun “Load Setup Defaults” in BIOS Setup Utility.
TRTC battery
TMainboard
Invalid System Configuration Data
TRun “Load Setup Defaults” in BIOS Setup Utility.
TMainboard
Operating system not found
TRun the BIOS Setup Utility to check if the fixed disk and drive 
A are properly identified.
TCD/DVD-ROM drive
THard disk drive
TMainboard
Power-on indicator turns off and LCD is 
blank.
TPower source (battery pack and power adapter.) See “Power 
System Check” on page 93.
TEnsure every connector is connected tightly and correctly.
TReconnect the DIMM
TMainboard
Power-on indicator turns on and LCD
is blank.
TPower source (battery pack and power adapter.) See “Power 
System Check” on page 93.
TReconnect the LCD connector
THard disk drive
TLCD cable
TLCD inverter
TLCD
TMainboard
Power-on indicator turns on and LCD
is blank. But you can see POST on an
external CRT.
TReconnect the LCD connectors.
TLCD cable
TLCD inverter
TLCD
TMainboard
Power-on indicator turns on and a
blinking cursor shown on LCD during
POST.
TEnsure every connector is connected tightly and correctly.
TMainboard
Failure Fixed Disk
TReconnect the hard disk drive connector.
TRun “Load Setup Defaults” in BIOS Setup Utility.
THard disk drive
TMainboard 
						

							Chapter 497
No beep, power-on indicator turns off and 
LCD is blank.TPower source (battery pack and power adapter). See “Power 
System Check” on page 93.
TEnsure every connector is connected tightly and correctly. 
TReconnect the DIMM.
TLED board
TMainboard
No beep, power-on indicator turns on and 
LCD is blank.
TPower source (battery pack and power adapter). See “Power 
System Check” on page 93.
TReconnect the LCD connector
THard disk drive
TLCD inverter ID
TLCD cable
TLCD Inverter
TLCD
TMainboard
No beep, power-on indicator turns on and 
LCD is blank. But you can see POST on an 
external CRT. 
TReconnect the LCD connectors.
TLCD inverter ID
TLCD cable 
TLCD inverter
TLCD
TMainboard
No beep, power-on indicator turns on and a 
blinking cursor shown on LCD during 
POST.
TEnsure every connector is connected tightly and correctly.
TMainboard
No beep during POST but system runs 
correctly.
TSpeaker
TMainboard Error Message List
Error MessagesCheck or do the following in sequence: 
						

							98Chapter 4
Phoenix BIOS Beep Codes
CodeBeepsPOST Routine Description
02h Verify Real Mode
03h Disable Non-Maskable Interrupt (NMI)
04h Get CPU type
06h Initialize system hardware
08h Initialize chipset with initial POST values
09h Set IN POST flag
0Ah Initialize CPU registers
0Bh Enable CPU cache
0Ch Initialize caches to initial POST values
0Eh Initialize I/O component
0Fh Initialize the local bus IDE
10h Initialize Power Management
11h Load alternate registers with initial POST values
12h Restore CPU control word during warm boot
13h Initialize PCI Bus Mastering devices
14h Initialize keyboard controller
16h 1-2-2-3 BIOS ROM checksum
17h Initialize cache before memory autosize
18h 8254 timer initialization
1Ah 8237 DMA controller initialization
1Ch Reset Programmable Interrupt Controller
20h 1-3-1-1 Test DRAM refresh
22h 1-3-1-3 Test 8742 Keyboard Controller
24h Set ES segment register to 4 GB
26h Enable A20 line
28h Autosize DRAM
29h Initialize POST Memory Manager
2Ah Clear 215 KB base RAM
2Ch 1-3-4-1 RAM failure on address line xxxx*
2Eh 1-3-4-3 RAM failure on data bits xxxx* of low byte of memory bus
2Fh Enable cache before system BIOS shadow
30h 1-4-1-1 RAM failure on data bits xxxx* of high byte of memory bus
32h Test CPU bus-clock frequency
33h Initialize Phoenix Dispatch Manager
36h Warm start shut down
38h Shadow system BIOS ROM
3Ah Autosize cache
3Ch Advanced configuration of chipset registers
3Dh Load alternate registers with CMOS values
42h Initialize interrupt vectors
45h POST device initialization 
						

							Chapter 499
46h 2-1-2-3 Check ROM copyright notice
48h Check video configuration against CMOS
49h Initialize PCI bus and devices
4Ah Initialize all video adapters in system
4Bh QuietBoot start (optional)
4Ch Shadow video BIOS ROM
4Eh Display BIOS copyright notice
50h Display CPU type and speed
51h Initialize EISA board
52h Test keyboard
54h Set key click if enabled
58h 2-2-3-1 Test for unexpected interrupts
59h Initialize POST display service
5Ah Display prompt “Press F2 to enter SETUP”
5Bh Disable CPU cache
5Ch Test RAM between 512 and 640 KB
60h Test extended memory
62h Test extended memory address lines
64h Jump to User Patch1
66h Configure advanced cache registers
67h Initialize Multi Processor APIC
68h Enable external and CPU caches
69h Setup System Management Mode (SMM) area
6Ah Display external L2 cache size
6Bh Load custom defaults (optional)
6Ch Display shadow-area message
6Eh Display possible high address for UMB recovery
70h Display error messages
72h Check for configuration errors
76h Check for keyboard errors
7Ch Set up hardware interrupt vectors
7Eh Initialize coprocessor if present
80h Disable onboard Super I/O ports and IRQs
81h Late POST device initialization
82h Detect and install external RS232 ports
83h Configure non-MCD IDE controllers
84h Detect and install external parallel ports
85h Initialize PC-compatible PnP ISA devices
86h Re-initialize onboard I/O ports
87h Configure Motherboard Configurable Devices (optional)
88h Initialize BIOS Data Area
89h Enable Non-Maskable Interrupts (NMIs)
CodeBeepsPOST Routine Description 
						

							100Chapter 4
8Ah Initialize Extended BIOS Data Area
8Bh Test and initialize PS/2 mouse
8Ch Initialize floppy controller
8Fh Determine number of ATA drives (optional)
90h Initialize hard-disk controllers
91h Initialize local-bus hard-disk controllers
92h Jump to UserPatch2
93h Build MPTABLE for multi-processor boards
95h Install CD-ROM for boot
96h Clear huge ES segment register
97h Fixup Multiprocessor table
98h 1-2 Search for option ROMs. One long, two short beeps on checksum 
failure.
99h Check for SMART drive (optional)
9Ah Shadow option ROMs
9Ch Set up Power Management
9Dh Initialize security engine (optional)
9Eh Enable hardware interrupts
9Fh Determine number of ATA and SCSI drives
A0h Set time of day
A2h Check key lock
A4h Initialize Typematic rate
A8h Erase F2 prompt
AAh Scan for F2 key stroke
ACh Enter SETUP
AEh Clear Boot flag
B0h Check for errors
B2h POST done- prepare to boot operating system
B4h 1 One short beep before boot
B5h Terminate QuietBoot (optional)
B6h Check password (optional)
B9h Prepare Boot
BAh Initialize DMI parameters
BBh Initialize PnP Option ROMs
BCh Clear parity checkers
BDh Display MultiBoot menu
BEh Clear screen (optional)
BFh Check virus and backup reminders
C0h Try to boot with INT 19
C1h Initialize POST Error Manager (PEM)
C2h Initialize error logging
C3h Initialize error display function
CodeBeepsPOST Routine Description