Acer Travelmate 4520 Service Guide

Chapter 471
System Error – No Beep
DMA Test Failed DIMM
System board
Software NMI Failed DIMM
System board
Fail-Safe Timer NMI Failed DIMM
System board
Device Address Conflict Run the Setup Utility, then press F9 to load the system 
defaults.
RTC battery
System board
Allocation Error for device Run the Setup Utility, then press F9 to load the system 
defaults.
RTC battery
System board
Failing Bits: nnnn DIMM
BIOS ROM
System board
Fixed Disk n None
Invalid System Configuration Data BIOS ROM
System board...

72Chapter 4
POST Beep Codes
No beep, power indicator turns on, the LCD 
screen is blank, but you can view POST 
when connected to an external CRT. Reconnect the LCD-CCD cable.
LCD-CCD cable 
Inverter board
LCD panel
System board
No beep, power indicator turns on and a 
blinking cursor appears on screen during 
POST.Ensure every internal cables are properly and securely 
connected. 
System board
No beep during POST but system runs 
correctly. Speaker
System board
CodeBeepsPOST Routine Description
02h...

Chapter 473
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
46h...

74Chapter 4
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...

Chapter 475
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...

76Chapter 4
F0h Initialize interrupt vectors
F1h Initialize Run Time Clock
F2h Initialize video
F3h Initialize System Management Mode
F4h 1 Output one beep before boot
F5h Boot to Mini DOS
F6h Clear Huge Segment
F7h Boot to Full DOS
CodeBeepsPOST Routine Description
Acer TM 4520 SG.book  Page 76  Friday, June 22, 2007  5:43 PM 

Chapter 477
Index of Symptom-to-FRU Error Message
NOTE:  If the symptom or error for your problem condition is not listed in this section, refer to the 
“Undetermined Problems” section on page 81.
LCD-related Symptoms 
Power-related Symptoms
Symptom/ErrorAction in Sequence
LCD backlight doesnt work
LCD is too dark
LCD brightness cannot be adjusted
LCD contrast cannot be adjustedRun the Setup Utility, then press F9 to load the system 
defaults.
Reconnect the LCD-CCD cable.
Keyboard (if contrast and...

78Chapter 4
Memory-related Symptom
Audio-related Symptoms
Power Management-related Symptoms 
Symptom / ErrorAction in Sequence
Memory count (size) appears different from 
actual size.Run the Setup Utility, then press F9 to load the system 
defaults.
DIMM
System board
Symptom / ErrorAction in Sequence
In Windows multimedia programs, no 
sound comes from the computer. Audio driver
Speaker
System board
Internal speakers emit noise or emit no 
sound.Speaker
System board
Symptom / ErrorAction in Sequence
The...

Chapter 479
I/O-related Symptoms  
Symptom / ErrorAction in Sequence
System configuration values does not 
match the installed devices. Run the Setup Utility, then press F9 to load the system 
defaults.
Reconnect hard disk/CD-ROM/diskette drives.
External display does not work correctly. Press Fn+F5, LCD/CRT/both display switching
System board
USB does not work correctly System board
Print problems Run printer self-test.
Printer driver
Printer cable
Printer
System board
Keyboard (one or more keys) does...

80Chapter 4
Intermittent Problems
Intermittent system hang problems can be caused by a variety of reasons that have nothing to do with a 
hardware defect, such as cosmic radiation, electrostatic discharge, or software errors. FRU replacement 
should be considered only when a recurring problem exists.
When analyzing an intermittent problem, do the following:
1.Run the advanced diagnostic test for the system board in loop mode at least ten times.
2.If no error is detected, do not replace any FRU.
3.If any...