Monday, March 14, 2016

LENOVO LAPTOP - Lenovo N21 Chromebook – Checking the charger – Disassembling procedure – How to remove the case – How to remove the speakers – How to remove the LCD Module – Laptop repair and service

Category: Laptop Repair and Service 

Contents of this article 

  • Checking the AC adapter
  • Removing the case
  • Disassembling the LCD Display

Lenovo N21 Chromebook

Checking the ac power adapter
If the computer fails only when the ac power adapter is used, refer to the information in this topic to check the ac power adapter.
If the power-on indicator does not turn on, check the power cord of the ac power adapter for correct continuity and installation.
To check the ac power adapter, do the following:
1. Unplug the ac power adapter cable from the computer.
2. Measure the output voltage across the plug of the ac power adapter cable. The correct voltages are shown in the following table.
Note: The output voltage across pin 2 might differ from the voltage that you measure.
3. Depending on the voltage that you measure, do one of the following:
# If the voltage is not correct, replace the ac power adapter.
# If the voltage is acceptable, do the following:
a. Replace the system board.
b. If the problem persists, call the Customer Support Center.
Note: Noise from the ac power adapter does not always indicate a defect.
Remove the upper case and the battery
Step 1. Pry the four rubbers out of their recesses 1 2 3 4.
Note: Each recess is marked with a number, please make sure that all rubbers are put in the right recesses when installing.
Step 2. Remove the ten screws 5.

Step 3. Turn over the Chromebook and open the LCD cover.
Step 4. Use a pry bar to slide through the grooves between the upper case and the base cover 6, and then slowly lift the upper case until the keyboard socket appears 7.
Step 5. Unplug the battery cable 8.
Note: The Chromebook will be powered on automatically when LCD cover is open. Therefore, please make sure that the battery cable is unplugged before doing the following operations.
Step 6. Detach the touchpad cable 9.
Step 7. Open the keyboard socket 10, pull out the keyboard cable 11, and then remove the upper case in the direction shown by arrow 12.
Step 8. Remove the three screws 13 and then remove the battery pack in the direction shown by arrow 14.
Remove the speakers
Step 1. Unplug the speakers’ cable from the system board 1.
Step 2. Remove the four screws 2 and then remove the speaker modules 3.
Remove the LCD module
Step 1. Unplug the LCD cable 1.
Step 2. Remove the four screws 2 that fix the LCD module to the base cover.
Step 3. Lift up the LCD module to detach it from the base cover 3.
Remove the LCD bezel
Step 1. Pry the six rubber pads 1 from the LCD bezel.
Step 2. Remove the six screws 2.
Step 3. Insert the screwdriver between one inner side of the LCD bezel and the LCD panel and then carefully pull the LCD bezel outwards. Repeat this action along the inner edges of the LCD bezel until all hooks that secure the LCD bezel are detached.
Step 4. Remove the LCD bezel 3.