Wednesday, May 25, 2016

Lenovo tab A7-50 – Disassembling procedure – How to test the AC adapter – How to remove the battery – Tablet repair and service

Category: Laptop Repair and Service 

Contents of this article 

  • How to test the AC adapter 
  • How to remove the case 
  • How to remove battery 

Lenovo Tab A7-50

To verify a symptom, follow the steps below:
1. Turn off the computer.
2. Remove the battery pack.
3. Connect the AC adapter.
4. Make sure that power is supplied when you turn on the computer.
5. Turn off the computer.
6. Disconnect the AC adapter and install the charged battery pack.
7. Make sure that the battery pack supplies power when you turn on the computer.
If you suspect a power problem, see the appropriate one of the following power supply checkouts:
“Checking the Computer AC Charger”
“Checking the internal battery status”
Checking the Computer AC Charger
When you use the computer AC Charger to charge the tablet but no power is charged, see the instructions in this topic to check the computer AC Charger. To check the computer AC Charger, do the following:
1. Disconnect the micro-USB cable from the tablet.
2. Measure the output voltage across the connector marked B of the micro-USB cable. Refer to the following figure:
Note: The output voltage across pin 3 of the micro-B connector might be different from the one you are servicing.
3. If the voltage is not correct, replace the micro-USB cable.
4. If the voltage is acceptable, replace the system board.
Checking the internal battery status
To check the battery status of the tablet, do either of the following:
Approximate information about the battery status
Get the approximate status of the battery at any time by checking the battery status icon on the system bar in the upper-right corner of the screen. The shorter the green bar is, the less the battery power remains.
Accurate information about the battery status
To get the accurate information about the battery status of the tablet, do the following:
1. Open the Android Settings screen.
To open the Android Settings screen, do either of the following:
From the main Home screen, touch the Android Settings icon on
Lenovo Launch Zone. The Android Settings screen is displayed.
Pull down the application icon from the action bar and then touch Settings. The Android Settings screen is displayed.
2. Touch Battery in the Device section on the Android Settings screen.
3. The accurate percentage of the remaining battery power is shown on the screen.
DISASSEMBLING PROCEDURE 
How to remove Rear cover and side key
1. Open the card slot cover on the rear cover using a guitar pick.
2. Remove screw 1 in the card slot recess.
3. Hold the tablet in one hand and use a guitar pick to unlock the rear cover from the tablet along the joint line as shown in the figure below.
4. Remove the rear cover.
How to remove Battery pack
1. Remove screw 1 for fixing the steel frame on the battery connector
2. Remove the steel frame from the front module as shown in the figure below.
3. Detach the battery FPC from its connector on the PCBA using a guitar pick.
4. Detach the battery pack from its seat by inserting a guitar pick into the joint surface and then cutting along the joint line in the direction shown in the figure below.
5. Remove the battery pack from the front module of the tablet.