Acer Aspire 8940 Service Guide

Chapter 241
4.In flash BIOS, the message Please do not remove AC Power Source displays.
NOTE: If the AC power is not connected, the following message displays.
Plug in the AC power to continue.
5.Flash is complete when the message Flash programming complete displays.  

42Chapter 2
WinFlash Utility
Perform the following steps to use the WinFlash Utility:
1.Double-click the WinFlash executable.
2.Click OK to begin the update. A progress screen displays. 

Chapter 243
Remove HDD/BIOS Password Utilities
This section provides you with details about removing HDD/BIOS password:
Remove HDD Password:
If you key in the wrong HDD password three times, an error code is generated.
To reset the HDD password, perform the following steps:
1.On a different machine, run the HDD_PW.EXE file along with the error code generated. For example:
hdd_pw 15494 0
2.Select an option to generate upper case or lower case ASCII code for unlocking the HDD. 
3.Two strings are generated...

44Chapter 2
Removing BIOS Passwords:
If you key in the wrong Supervisor password three times, an error code is generated and system is disabled.
To unlock the BIOS, perform the following steps:
1.On a different machine, run the BIOS_PW.EXE file along with the error code generated. For example:
bios_pw 14452 0
2.Four ASCII strings are generated as output. Select and note down any one of the strings.
3.Reboot the machine with the locked BIOS and then use either any of the strings as the BIOS user 
password. 

Chapter 245
Using Boot Sequence Selector
The Boot Sequence Selector allows the boot order to be changed without accessing the BIOS. To use Boot 
Sequence Selector, perform the following steps:
1.Enter into DOS.
2.Execute BS.exe to display the usage screen.
3.Select the desired boot sequence by entering the corresponding sequence. For example, enter BS2 to 
change the boot sequence to HDD | CD ROM | LAN | Floppy. 

46Chapter 2
Using DMITools
The DMI (Desktop Management Interface) Tool copies BIOS information to EEPROM to be used in the DMI 
pool for hardware management. 
When the BIOS displays Verifying DMI pool data it is checking that the table correlates with the hardware 
before sending to the operating system (Windows, etc.).
To update the DMI Pool, perform the following steps:
1.Boot into DOS.
2.Execute dmitools. The following messages report to screen to confirm completion:
• dmitools /r ==> Read dmi string...

Chapter 247
Using the LAN MAC EEPROM Utility
You can use the MAC.BAT utility to write the MAC.CFG file to the EEPROM under DOS mode.
1.Use a text editor (for example: Notepad) to open the MAC.CFG file. You can see the MAC.CFG contents 
as below:
2.In DOS mode, run the MAC.BAT file to write MAC values to eeprom. WriteData = ‘001122334455 MAC value
StartAddr=7A MAC address
WriteLeng=6 MAC value length
KeepByte=0 don’t care 

48Chapter 2 

Chapter 349
Machine Disassembly and Replacement
This chapter contains step-by-step procedures on how to disassemble the notebook computer for 
maintenance and troubleshooting.
Disassembly Requirements
To disassemble the computer, you need the following tools:
•Wrist grounding strap and conductive mat for preventing electrostatic discharge
•Flat screwdriver
•Philips screwdriver
•Plastic flat screwdriver
•Plastic tweezers
NOTE: The screws for the different components vary in size. During the disassembly...

50Chapter 3
General Information
Pre-disassembly Instructions
Before proceeding with the disassembly procedure, make sure that you do the following:
1.Turn off the power to the system and all peripherals.
2.Unplug the AC adapter and all power and signal cables from the system. 
3.Place the system on a flat, stable surface. 
4.Remove the battery pack.
Disassembly Process
The disassembly process is divided into the following stages:
•External module disassembly
•Main unit disassembly
•LCD module...