Acer Aspire 2420 Service Guide

							Chapter 4111
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 screen 
Wrong color displayedReconnect the LCD connector
LCD inverter ID
LCD cable
LCD inverter
LCD
System board
LCD has extra horizontal or vertical lines 
displayed.LCD inverter ID
LCD inverter
LCD cable
LCD
System board
Indicator-Related Symptoms
Symptom / ErrorAction in Sequence
Indicator incorrectly remains off or on, but 
system runs correctlyReconnect the inverter board
Inverter board
System board
Power-Related Symptoms
Symptom / ErrorAction in Sequence
Power shuts down during operation Power source (battery pack and power adapter). See “Power 
System Check” on page 99. 
Battery pack
Power adapter
Hard drive & battery connection board
System board
The system doesn’t power-on. Power source (battery pack and power adapter). See “Power 
System Check” on page 99. 
Battery pack
Power adapter
Hard drive & battery connection board
System board 
						

							11 2Chapter 4
The system doesn’t power-off. Power source (battery pack and power adapter). See “Power 
System Check” on page 99. 
Hold and press the power switch for more than 4 seconds.  
System board
Battery can’t be charged See “Check the Battery Pack” on page 101. 
Battery pack
System board
PCMCIA-Related Symptoms
Symptom / ErrorAction in Sequence
System cannot detect the PC Card 
(PCMCIA) PCMCIA slot assembly
System board
PCMCIA slot pin is damaged. PCMCIA slot assembly
Memory-Related Symptoms
Symptom / ErrorAction in Sequence
Memory count (size) appears different from 
actual size.Enter BIOS Setup Utility to execute “Load Default Settings, 
then reboot system.
DIMM
System board
Speaker-Related Symptoms
Symptom / ErrorAction in Sequence
In Windows, multimedia programs, no 
sound comes from the computer. Audio driver
Spe ak er
System board
Internal speakers make noise or emit no 
sound.Spe ak er
System board
Power Management-Related Symptoms
Symptom / ErrorAction in Sequence
The system will not enter hibernation See “Save to Disk (S4)” on page 37.
Keyboard (if control is from the keyboard)
Hard disk drive
System board
The system doesnt enter hibernation mode 
and four short beeps every minute.Press Fn+
oand see if the computer enters hibernation mode.
Touchpad
Keyboard
Hard disk connection board
Hard disk drive
System board
The system doesn’t enter standby mode 
after closing the LCDSee “Save to Disk (S4)” on page 37.
LCD cover switch
System board Power-Related Symptoms
Symptom / ErrorAction in Sequence 
						

							Chapter 411 3
The system doesnt resume from 
hibernation mode.See “Save to Disk (S4)” on page 37.
Hard disk connection board
Hard disk drive
System board
The system doesnt resume from standby 
mode after opening the LCD.See “Save to Disk (S4)” on page 37.
LCD cover switch
System board
Battery fuel gauge in Windows doesn’t go 
higher than 90%. Remove battery pack and let it cool for 2 hours.
Refresh battery (continue use battery until power off, then 
charge battery).
Battery pack
System board
System hangs intermittently. Reconnect hard disk/CD-ROM drives. 
Hard disk connection board
System board
Peripheral-Related Symptoms
Symptom / ErrorAction in Sequence
System configuration does not match the 
installed devices. Enter BIOS Setup Utility to execute “Load Default Settings”, 
then reboot system.
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. Ensure the “Parallel Port” in the “Onboard Devices 
Configuration” of BIOS Setup Utility is set to Enabled.
Onboard Devices Configuration
Run printer self-test.
Printer driver
Printer cable
Printer
System Board
Serial or parallel port device problems. Ensure the “Serial Port” in the Devices Configuration” of 
BIOS Setup Utility is set to Enabled.
Device driver
Device cable
Device
System board
Keyboard/Touchpad-Related Symptoms
Symptom / ErrorAction in Sequence
Keyboard (one or more keys) does not 
work.Reconnect the keyboard cable.
Keyboard
System board Power Management-Related Symptoms
Symptom / ErrorAction in Sequence 
						

							11 4Chapter 4
NOTE: If you cannot find a symptom or an error in this list and the problem remains, see “Undetermined 
Problems” on page 116. Touchpad does not work. Reconnect touchpad cable.
Touchpad board
System board
Modem-Related Symptoms
Symptom / ErrorAction in Sequence
Internal modem does not work correctly. Modem phone port
modem combo board
System board Keyboard/Touchpad-Related Symptoms
Symptom / ErrorAction in Sequence 
						

							Chapter 411 5
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 10 times.
2.If no error is detected, do not replace any FRU.
3.If any error is detected, replace the FRU. Rerun the test to verify that there are no more errors.  
						

							11 6Chapter 4
Undetermined Problems
The diagnostic problems does not identify which adapter or device failed, which installed devices are incorrect, 
whether a short circuit is suspected, or whether the system is inoperative.  
Follow these procedures to isolate the failing FRU (do not isolate non-defective FRU).
NOTE: Verify that all attached devices are supported by the computer.
NOTE: Verify that the power supply being used at the time of the failure is operating correctly. (See “Power 
System Check” on page 99.):
1.Power-off the computer.
2.Visually check them for damage. If any problems are found, replace the FRU.
3.Remove or disconnect all of the following devices:
Non-Acer devices
Printer, mouse, and other external devices
Battery pack
Hard disk drive
DIMM 
CD-ROM/Diskette drive Module
PC Cards
4.Power-on the computer.
5.Determine if the problem has changed.
6.If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU.
7.If the problem remains, replace the following FRU one at a time. Do not replace a non-defective FRU:
System board
LCD assembly 
						

							Chapter 511 7
Top View
Jumper and Connector Locations
Chapter 5 
						

							11 8Chapter 5
Bottom View 
						

							Chapter 511 9
Clearing Password Check and BIOS Recovery
This section provide you the standard operating procedures of clearing password and BIOS recovery for 
Aspire 2920/2920Z/2420. Aspire 2920/2920Z/2420 provide one Hardware Open Gap on main board for 
clearing password check, and one Hotkey for enabling BIOS Recovery.
Clearing Password Check
Hardware Open Gap Description
HW Gap position on M/B space:
Gap name in Aspire 2920/2920Z/2420 is G71
 
Steps for Clearing BIOS Password Check
If users set BIOS Password ( Supervisor Password and/or User Password ) for a security reason, BIOS will 
ask the password during systems POST or when systems enter to BIOS Setup menu. However, once it is 
necessary to bypass the password check, users need to short the HW Gap to clear the password by the 
following steps:
qPower Off a system, and remove HDD, AC and Battery from the machine.
qOpen the back cover of the machine, and find out the HW Gap on M/B as picture.
qUse an electric conductivity tool to short the two points of the HW Gap.
qPlug in AC, keep the short condition on the HW Gap, and press Power Button to power on the 
system till BIOS POST finish. Then remove the tool from the HW Gap.
qRestart system. Press F2 key to enter BIOS Setup menu.
qIf there is no Password request, BIOS Password is cleared. Otherwise, please follow the steps and 
try again.
NOTE: The steps are only for clearing BIOS Password ( Supervisor Password and User Password ).
Hardware Default Setting Operation Description
Gap Open (Normal) Short (Clearing Password Check) 
						

							120Chapter 5
BIOS Recovery by Crisis Disk
BIOS Recovery Boot Block:
BIOS Recovery Boot Block is a special block of BIOS. It is used to boot up the system with minimum BIOS 
initialization. Users can enable this feature to restore the BIOS firmware to a successful one once the previous 
BIOS flashing process failed.
BIOS Recovery Hotkey:
The system provides a function hotkey: Fn+Esc, for enable BIOS Recovery process when system is powered 
on during BIOS POST. To use this function, it is strongly recommended to have the AC adapter and Battery 
present. If this function is enabled, the system will force the BIOS to enter a special BIOS block, called Boot 
Block.
Steps for BIOS Recovery by Crisis Disk:
Before doing this, one Crisis Disk should be prepared ready in hand. The Crisis Disk could be made by 
executing the Crisis Disk program in another system with Windows XP OS.
Follow the steps below:
1.Power Off system.
2.Insert the Crisis Disk to a USB floppy drive which is attached to the BIOS flash failed machine.
3.In the power-off state, press Fn+Esc and hold them and then press Power Button. The system should be 
powered on with Crisis BIOS Recovery process.
4.BIOS Boot Block starts to restore the BIOS code from the Crisis floppy disk to BIOS ROM on the failed 
machine.
5.If the Crisis flashing process is finished, the system will restart.
If the Crisis Recovery process is finished, the system should be powered on with successful and workable 
BIOS. Then a person can update the latest version BIOS for this machine by regular BIOS flashing process.