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...

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...

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...

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...

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...

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...

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...

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...

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...

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...