Acer Travelmate 520 Service Guide

Chapter 365
Removing the Modem Cable
1.At CN21 and CN22, disconnect the modem cable from the main board, then remove the modem cable 
from the main board. 

66Chapter 3 

Chapter 467
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 re-create the failure by running the diagnostic test or by repeating 
the same operation.
3.Use the following table with the verified symptom to determine...

68Chapter 4
System Check Procedures
Diskette Drive Check
Do the following to isolate the problem to a controller, driver, cable or diskette.  A write-enabled, diagnostic 
diskette is required.
NOTE: 
Make sure that the diskette does not have more than one label attached to it.  Multiple labels can cause 
damage to the drive or cause the drive to fail. 
Do the following to select the test device. 
1.
Boot from the diagnostics diskette and start the PQA program.
2.
Go to the diagnostic Diskette Drive in...

Chapter 469
The following auxiliary input devices are supported by this computer:
TNumeric keypad
TExternal keyboard
If any of these devices do not work, reconnect the cable connector and repeat the failing operation. 
Memory Check
Memory errors might stop system operations, show error messages on the screen, or hang the system.
1.
Boot from the diagnostics diskette and start the PQA program (please refer to “Running PQA Diagnostics 
Program”).
2.
Go to the diagnostic memory in the test items.
3.
Press...

70Chapter 4
Check the Battery Pack 
To check the battery pack, do the following:
1.
Power off the computer. 
2.
Remove the battery pack and measure the voltage between battery terminals 1(+) and 7(ground). See the 
following figure
3.
If the voltage is still less than 8.0 Vdc after recharging, replace the battery. 
To check the battery charge operation, use a discharged battery pack or a battery pack that has less than 50% 
of the total power remaining when installed in the computer. 
If the battery...

Chapter 471
Index of Error Message
The symptom-to-FRU index lists the symptoms and errors and their possible causes. The most likely cause is 
listed first.
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.
This index can also help you determine the next possible FRU to be replaced when servicing a computer.
If the symptom is not...

72Chapter 4
Memory size found by POST differed from CMOS Run “Load Default Settings” in BIOS Setup Utility.
DIMM
System board
Diskette drive A error Check that the drive is defined with the proper diskette 
type in BIOS Setup Utility.
Diskette Drive Check. 
Incorrect Drive A type - run SETUP Check that the drive is defined with the proper diskette 
type in BIOS Setup Utility
Diskette Drive Check. 
System cache error - Cache disabled CPU board
System board
CPU ID CPU board
System board
DMA Test Failed...

Chapter 473
No-Beep Symptoms
Symptom / ErrorAction in Sequence
No beep, power-on indicator turns off and LCD is 
blank.Power source (battery pack and power adapter). 
Power System Check. 
Ensure every connector is connected tightly and 
correctly. 
Reconnect the DIMM.
CPU board
System board.
No beep, power-on indicator turns on and LCD is 
blank.Power source (battery pack and power adapter).
Power System Check.  
Reconnect the LCD connectors
Hard disk drive
LCD inverter ID
LCD cable
Inverter
LCD
System...

74Chapter 4
Index of Symptom-to-FRU Error Message
LCD-Related Symptoms
Symptom / ErrorAction in Sequence
LCD backlight doesnt work
LCD is too dark
LCD brightness cannot be adjusted
LCD contrast cannot be adjustedEnter BIOS Utility to execute “Load Setup Default 
Settings”, then reboot system.
Reconnect the LCD connectors.
Keyboard (if contrast and brightness function key 
doesnt work).
LCD inverter ID
LCD cable
LCD inverter
LCD
System board
Unreadable LCD screen 
Missing pels in characters
Abnormal...