Wednesday, March 16, 2016

LENOVO LAPTOP – Lenovo ThinkPad Yoga 15 – Battery charger test procedure – Battery pack test procedure – How to test the RTC battery - Password reset - laptop repair and service

Category: Laptop Repair and Service 

Contents of this article

  • How to test the AC adapter 
  • How to test the RTC battery 
  • How to remove passwords  

 


Lenovo ThinkPad Yoga 15

Power system checkout 
To verify a power symptom, do the following:
1. Turn off the computer.
2. Connect the ac power adapter.
3. Turn on the computer. If the computer can be turned on, it means that either the battery pack or the ac power adapter is functional.
4. Insert a straightened paper clip into the emergency reset hole to reset the computer. If the computer is still powered on, it means that the ac power adapter is functional.
5. Turn off the computer.
6. Disconnect the ac power adapter and turn on the computer. If the computer can be turned on, it means that the battery pack is functional.
Checking the built-in battery and operational charging”
 “Checking the coin-cell battery”
Checking the ac power adapter
You are here because the computer fails only when the ac power adapter is used.
If the power problem occurs only when the docking station or the port replicator is used, replace the docking station or the port replicator.
If the system status indicator does not blink three times when an ac power source is connected, check the power cord of the ac power adapter for correct continuity and installation.
1. Unplug the ac power adapter cable from the computer.
2. Measure the output voltage at the plug of the ac power adapter cable. See the following illustration
Note: Output voltage of pin 2 of the ac power adapter might differ from the one you are servicing.
3. If the voltage is not correct, replace the ac power adapter.
4. If the voltage is acceptable, replace the system board.
Note: Noise from the ac power adapter does not always indicate a defect.
Checking the built-in battery and operational charging
This computer supports only batteries specially designed for this specific system and manufactured by Lenovo or an authorized builder. The system does not support unauthorized batteries or batteries designed for other systems. If an unauthorized battery or a battery designed for another systems is installed, the system will not charge.
To check for detailed battery status information, do the following:
For 7: Open the Power Manager program and click the Battery tab.
For 8.1: Open the Lenovo Settings program and click OK.
To check whether the battery charges properly during operation, do the following:
1. Discharge the battery until the remained battery power is less than 50%.
2. Connect the computer to ac power to charge the battery.
If the battery status icon in the Windows notification area indicates that the battery is not charging, remove the battery and let it return to room temperature.
3. Reinstall the battery. If the battery is still not charging, replace the battery pack.
4. Check the battery status icon again. If the same error still exists, replace the system board.
Checking the coin-cell battery
To check the coin-cell battery, do the following:
1. Disconnect the battery connector.
2. Remove the coin-cell battery.  
Measure the voltage of the coin-cell battery. See the following illustration
If the voltage is correct, replace the system board.
If the voltage is not correct, replace the coin-cell battery.
If the coin-cell battery discharges quickly after replacement, replace the system board.
How to remove the power-on password
If a supervisor password has been set and is known to the service technician, do the following to remove the power-on password:
1. Turn on the computer.
2. When the ThinkPad logo comes up, immediately press F1.
3. Type the supervisor password to enter the ThinkPad Setup program.
4. Select Security.
5. Select Password.
6. Select Power-On Password.
7. Type the current supervisor password in the Enter Current Password field. Then leave the Enter
New Password field blank, and press Enter twice.
8. In the Changes have been saved window, press Enter.
9. Press F10 to save changes and exit the ThinkPad Setup program.
How to remove the hard disk password
To remove a user hard disk password that has been forgotten, when the supervisor password and master hard disk password are known, do the following:
1. Turn on the computer.
2. When the ThinkPad logo comes up, immediately press F1 to enter the ThinkPad Setup program.
3. Select Security.
4. Select Password.
5. Select Hard-disk x password, where x is the letter of the hard disk drive. A pop-up window opens.
6. Select Master hard disk password.
7. Type the current master hard disk password in the Enter Current Password field. Then leave the Enter
New Password field blank, and press Enter twice.
8. Press F10. 9. Press F10 to save changes and exit the ThinkPad Setup program.
The user hard disk password and the master hard disk password have been removed.