Acer Extensa 900 Maintenance Manual

                                                                                                            Theory of Operation  4-25  
4.2.11.2 AC Power Adapter
The computer is equipped with a universal AC power adapter that converts AC voltage  
into DC voltage (approx. 46 Watts of power) used to operate the notebook and charge 
the batteries. The specifications for the AC adapter include:
¨Input Voltage:  100 to 250 VAC
¨Input Current:  Approximately 1.5 Amps
¨Input Frequency: 50 to 60 Hz
4.2.12...

                                                                                                  Troubleshooting Procedures  5-1
5
Troubleshooting Procedures
5.1 Introduction
This section provides an overview of the fault isolation process, provides guidelines for 
isolating 900 Series computer malfunctions to replaceable subassemblies and provides 
instructions for executing diagnostics and interpreting error messages.
5.2 Overview of Fault Isolation Process
The fault isolation process (summarized in...

5-2   Troubleshooting Procedures
®
Figure 5-1  Notebook Computer Troubleshooting Flow Chart
START
COMPUTER
TROUBLE
INDICATION
?
DEAD
COMPUTER
SYMPTOMS
?
RUN
SELF TEST
ERROR
MESSAGE
?
MODEM
PROBLEM
?
RUN
DIAGNOSTICS
DIAGNOSTICS
ERROR MSG
?
NO
YES NO
YESSee Paragraph
5.3.5 NO
YESSee Paragraphs
5.3.3.1 and 5.3.3.2
NO
See Paragraphs
5. 3.1 &  5.3.2 NOYES
See Paragraph
 5.5 
When Power button 
is pressed, no indication
of power is present (dark
LCD, no Status icons lit, 
no disk drive activity, etc.)
Press...

                                                                                           Troubleshooting Procedures    5-3  
5.3  Troubleshooting Procedures
The built-in self test program and the disk resident diagnostics program (PC-Doctor) 
are useful tools in computer troubleshooting. However, if the computer has a power, 
keyboard or display problem, you must first solve this problem before running 
diagnostics. If the computer powers up and displays messages on the LCD or emits a 
series of beeps,...

5-4   Troubleshooting Procedures
Table 5-1 contains fault isolation information for Display Problems on the notebook. 
Symptoms are listed along the left side of the chart and the various Display FRUs are 
listed along the top of the chart. Within the body of the table are the probabilities of 
each of the FRUs causing that particular problem. For example, a single display line 
on the screen is most likely caused by the LCD Panel or Display Cable; other components 
have a low probability of causing the...

                                                                                           Troubleshooting Procedures    5-5  
5.3.3.1 POST Error Messages
Upon successful completion of Power On Self Test, the computer automatically loads 
its operating system and other built-in utilities. If POST fails to complete successfully, 
the display shows one of the error messages described in Table 5-2.
Note: In the event of a hardware problem that affects the display, the Notebook 
also communicates errors via...

5-6   Troubleshooting Procedures
Table 5-2  Power On Self Test Error Messages
Message Possible Cause Action
Diskette drive A failure
The drive failed or is missing. Check the drive to determine the
problem.
Diskette read failure - press
F1 to retry boot, F2 for
SETUP utilityThe disk is either not
formatted or is defective.Replace the disk with a bootable
disk and retry.
Display adapter failed,
using alternateThe primary video adapter
failed.Check the primary video
adapter.
Gate A20 failure
The keyboard...

                                                                                           Troubleshooting Procedures    5-7  
Table 5-2  Post Error Messages (continued)
Message Possible Cause Action
No boot device available -
press F1 to retry boot, F2
for SETUP utilityEither disk drive A:, the fixed
diskette, or both the disk and
fixed diskette are defective.Try rebooting. If the problem
persists, replace the disk or the
fixed diskette.
No boot sector on fixed
disk - press F1 to retry
boot, F2 for...

5-8   Troubleshooting Procedures
5.3.3.2 POST Beep Error Messages
In the event of a hardware problem that affects the display, the Notebook also 
communicates errors via a series of beeps. These codes may be heard over the systems 
speaker as a series of beeps (long and short duration). The interpretation of the beep 
codes is provided in Table 5-3.
To recover from a self test error, try cycling power to the computer. Also, press 
Ctrl-Alt-Esc to ensure that the Setup configuration is correct. In...