Acer Aspire 4920 Service Guide

							Chapter 391
17.Detach the acetic tapes holding the FPC cable to the edge of the LCD panel. 
18.Detach the acetic tape securing the FPC connector.
19.Disconnect the FPC cable from the LCD panel. 
Removing the LCD Brackets
1.See “Removing the Battery Pack” on page 53.
2.See “Removing the Lower Cover” on page 55.
3.See “Removing the DIMM” on page 56.
4.See “Removing the WLAN Board Module” on page 57.
5.See “Removing the Hard Disk Drive Module” on page 58.
6.See “Removing the Optical Drive Module” on page 59.
7.See “Removing the CPU Heatsink Module” on page 62.
8.See “Removing the CPU” on page 63.
9.See “Removing the Keyboard” on page 64.
10.See “Removing the Middle Cover” on page 65.
11 .See “Removing the LCD Module” on page 68.
12.See “Removing the LCD Bezel” on page 86.
13.See “Removing the Inverter Board” on page 88.
14.See “Removing the LCD with Brackets” on page 89.
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							92Chapter 3
15.Remove the four screws (H) securing the left and right LCD brackets to remove the brackets. 
Removing the LCD Module Hinges
1.See “Removing the Battery Pack” on page 53.
2.See “Removing the Lower Cover” on page 55.
3.See “Removing the DIMM” on page 56.
4.See “Removing the WLAN Board Module” on page 57.
5.See “Removing the Hard Disk Drive Module” on page 58.
6.See “Removing the Optical Drive Module” on page 59.
7.See “Removing the CPU Heatsink Module” on page 62.
8.See “Removing the CPU” on page 63.
9.See “Removing the Keyboard” on page 64.
10.See “Removing the Middle Cover” on page 65.
11 .See “Removing the LCD Module” on page 68.
12.See “Removing the LCD Bezel” on page 86.
13.See “Removing the Inverter Board” on page 88.
14.See “Removing the LCD with Brackets” on page 89.
15.See “Removing the LCD Brackets” on page 91.
16.Remove the two screws (G) securing the left and right LCD module hinges.  
StepSize (Quantity)ColorTo r q u e
1~4 M2 x L3 (4) Silver 1.6 kgf-cm
StepSize (Quantity)ColorTo r q u e
1~2 M2.5 x L6 (2) Black 3.0 kgf-cm 
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							Chapter 393
17.Remove the left and right hinges from the LCD back cover. 
Removing the Antennas 
1.See “Removing the Battery Pack” on page 53.
2.See “Removing the Lower Cover” on page 55.
3.See “Removing the DIMM” on page 56.
4.See “Removing the WLAN Board Module” on page 57.
5.See “Removing the Hard Disk Drive Module” on page 58.
6.See “Removing the Optical Drive Module” on page 59.
7.See “Removing the CPU Heatsink Module” on page 62.
8.See “Removing the CPU” on page 63.
9.See “Removing the Keyboard” on page 64.
10.See “Removing the Middle Cover” on page 65.
11 .See “Removing the LCD Module” on page 68.
12.See “Removing the LCD Bezel” on page 86.
13.See “Removing the Inverter Board” on page 88.
14.See “Removing the LCD with Brackets” on page 89.
15.Detach the gasket tape holding the right antenna in place, remove the antenna bracket, then carefully 
remove the antenna.
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1. 
						

							94Chapter 3
16.Detach the gasket tape holding the left antenna in place, remove the antenna bracket, then carefully 
remove the antenna.
Removing the Microphones 
1.See “Removing the Battery Pack” on page 53.
2.See “Removing the Lower Cover” on page 55.
3.See “Removing the DIMM” on page 56.
4.See “Removing the WLAN Board Module” on page 57.
5.See “Removing the Hard Disk Drive Module” on page 58.
6.See “Removing the Optical Drive Module” on page 59.
7.See “Removing the CPU Heatsink Module” on page 62.
8.See “Removing the CPU” on page 63.
9.See “Removing the Keyboard” on page 64.
10.See “Removing the Middle Cover” on page 65.
11 .See “Removing the LCD Module” on page 68.
12.See “Removing the LCD Bezel” on page 86.
13.See “Removing the Inverter Board” on page 88.
14.See “Removing the LCD with Brackets” on page 89.
15.See “Removing the Antennas” on page 93.
16.Carefully remove the microphone cables from underneath the adhesive aluminum foil.
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1. 
						

							Chapter 395
17.Remove the microphones .
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							96Chapter 3
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							Chapter 497
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 recreate the failure by running the diagnostic tests or repeating the 
same operation.
3.Do not use any power sources when performing an assembly or disassembly procedures.
4.If any problems occur, you can perform the following visual inspection before you continue. 
TPower cords are properly connected and secured.
TThere are no obvious shorts or opens.
TThere are no burned or heated components.
TAll components appear normal.
Troubleshooting
Chapter 4
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							98Chapter 4
System Check Procedures
External CD/DVD-ROM Drive Check
Perform the following procedures to isolate the possible problem a controller, drive, or CD-ROM. 
NOTE: Make sure that the CD-ROM does not have any label attached to it. The label may damage the drive or 
cause drive failure.
1.Boot from the diagnostic disc and start the diagnostic programs.
2.See if CD-ROM Test is passed when the program runs the CD-ROM Test.
3.Follow onscreen instructions.
If an error occurs, reconnect the drive to the connector on the mainboard. If the error persists, do the following:
1.Reconnect the CD/DVD-ROM drive.
2.Replace the CD/DVD-ROM drive.
3.Replace the mainboard.
Keyboard or Auxiliary Input Device Check
Remove the external keyboard if the internal keyboard is to be tested.
If the internal keyboard does not work or an unexpected error occurs, make sure that the flexible cable 
extending from the internal keyboard is correctly connected to the mainboard. If the keyboard cable 
connection is correct, run the Keyboard Test. 
If the tests detect a keyboard problem, do the following procedures in sequence to correct the problems. Do 
not replace a non-defective FRU:
1.Reconnect the keyboard cable.
2.Replace the keyboard.
3.Replace the mainboard.
The following auxiliary input devices are supported by this computer:
TNumeric keypad
TExternal keyboard
If any of these devices do not function, reconnect the cable and repeat above procedures. 
Memory Check
NOTE: Make sure that the DIMM is properly installed into the connector. A loose connection can cause an 
error.
Do the following:
1.Boot from the diagnostic diskette and start the diagnostic program.
2.Go to the diagnostic memory in the test items.
3.Press F2 in the test items.
4.Follow onscreen instructions.
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							Chapter 499
Power System Check
Do the following:
1.Remove the battery pack.
2.Connect the power adapter and check the power supply.
3.Disconnect the power adapter and install the battery pack; then check that power supply.
If you suspect a power problem, see the appropriate power supply check in the following list:
T“Check the Power Adapter” on page 99
T“Check the Battery Pack” on page 99
Check the Power Adapter
Unplug the power adapter cable from the system and measure the output voltage at the plug of the power 
adapter cable. 
1.If the voltage is not correct, replace the power adapter.
2.If the voltage is within range, do the following:
a.Replace the System board.
b.If the problem is not resolved, see “Undetermined Problems” on page 112.
c.If the voltage is not correct, go to the next step.
NOTE: An audible noise from the power adapter does not always indicate a defect.
3.If the power-on indicator does not light up, check if the adapter’s power cord is properly connected to the 
system.
4.If the operational charge does not work, see “Check the Battery Pack” on page 99. 
Check the Battery Pack 
Do the following:
Using the software to identify whether a problem occurs while the battery pack during recharge or discharge:
1.Open Power Management in the Control Panel.
2.In Power Meter, confirm if the parameters for Current Power Source and Total Battery Power Remaining 
are correct.
3.Repeat the steps 1 and 2 for both battery and adapter.
Using the hardware to identify whether you should replace the battery pack or not:
1.Power off the system. 
2.Remove the battery pack and measure the voltage between terminals one (+) and seven (-). There are 
seven terminals totally. 
3.If the voltage is still less than 7.5 Vdc after recharging, replace the battery. 
If the battery status indicator does not light up, remove the battery pack . If the charge indicator still does not 
light up, replace the AC/DC charger board.  
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							100Chapter 4
Touchpad Check
If the touchpad doesn’t work, do the following  procedures in sequence to correct the problem. Do not replace 
a non-defective FRU:
1.After rebooting, run Tracking Pad PS2 Mode Driver. For example Syn touch driver.
2.Run utility with the PS/2 mouse function and check if the mouse is working.
3.If the PS/2 mouse does not work, then click if the main board to switch board FPC is connected properly.
4.If the main board to switch board FPC is connected correctly, then check if the FFC on the touch pad PCB 
is connected properly.
5.If the FFC on the touch pad PCB is connected correctly, check if LS851 JP1 Pin6 = 5V are pules. If yes, 
then replace switch board. If not, then go to the next step.
6.Replace the touch pad PCB.
7.If the touch pad still does not work, then replace the FPC on Track Pad PCB.
After you use the touchpad, the pointer drifts on the screen for a short time. This self-acting pointer movement 
will occur when a slight, steady pressure is applied to the touchpad pointer. This symptom is not a hardware 
problem. No actions are necessary to be taken if the pointer movement stops in a short period of time.
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1.