Acer Aspire 4720 Service Guide

Chapter 365
10.Disconnect the LCD cable from the rear of the LCD.
11 .Detach the microphone cable from the LCD cover and remove the microphone.
12.Remove the CCD module from the LCD cover as shown.
Disassembling the External Modules
Disassembling the HDD Module
1.Remove the two screws fastening the bracket to the HDD module.
2.Remove the bracket.
Disassembling the ODD Module
1.Remove the two screws holding the optical bracket.
2.Then remove the optical bracket from the optical disk drive. 

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
External Diskette Drive Check
Do the following to isolate the problem to a controller, driver, 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 diagnostics program.
2.See if FDD Test is passed as the...

Chapter 469
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 diagnostic program (please refer to main board).
2.Go to the diagnostic memory in the test items.
3.Press F2 in the test items.
4.Follow the instructions in the message window.
NOTE: Make sure that the DIMM is fully installed into...

70Chapter 4
Check the Power Adapter
Unplug the power adapter cable from the computer and measure the output voltage at the plug of the power 
adapter cable. See the following figure:
1.If the voltage is not correct, replace the power adapter.
2.If the voltage is within the range, do the following:
TReplace the System board.
TIf the problem is not corrected, see “Undetermined Problems” on page 84.
TIf the voltage is not correct, go to the next step.
NOTE: An audible noise from the power adapter does not...

Chapter 471
Check the Battery Pack 
To check the battery pack, do the following:
From Software:
1.Check out the Power Management in Control Panel
2.In Power Meter, confirm that if the parameters shown in the screen for Current Power Source and Total 
Battery Power Remaining are correct.
3.Repeat the steps 1 and 2, for both battery and adapter.
4.This helps you identify first the problem is on recharging or discharging. 
From Hardware:
1.Power off the computer. 
2.Remove the battery pack and measure the...

72Chapter 4
Power-On Self-Test (POST) Error Message 
The POST error message index lists the error message 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...

Chapter 473
Index of Error Messages
Error Code List
Error CodesError Messages
006 Equipment Configuration Error
Causes:
1. CPU BIOS Update Code Mismatch
2. IDE Primary Channel Master Drive Error
(THe causes will be shown before “Equipment Configuration 
Error”)
010 Memory Error at xxxx:xxxx:xxxxh (R:xxxxh, W:xxxxh) 
070 Real Time Clock Error
071 CMOS Battery Bad
072 CMOS Checksum Error
110 System disabled.
Incorrect password is specified.
 Battery critical LOW
In this situation BIOS will issue 4 short...

74Chapter 4
Real time clock error RTC battery
Run BIOS Setup Utility to reconfigure system time, then reboot 
system.
System board
Previous boot incomplete - Default configuration 
usedRun “Load Default Settings” in BIOS Setup Utility.
RTC battery
System board
Memory size found by POST differed from 
CMOSRun “Load Default Settings” in BIOS Setup Utility.
DIMM
System board
Diskette drive A error Check the drive is defined with the proper diskette type in BIOS 
Setup Utility
See “External Diskette Drive...