Saturday, 19 May 2018

Lenovo Thinkpad S531 – How to remove the power on password – How to reset the HDD password – How to test the AC adapter – How to Check the battery pack


Lenovo Thinkpad S531: 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.
If you suspect a power problem, see the appropriate one of the following power supply checkouts:
“Checking the ac power adapter”
“Checking the built-in battery and operational charging”
“Checking the backup 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.
To check the ac power adapter, do the following:
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.
To check for detailed battery status information, do the following:
For 7: Open the Power Manager program and click the Battery tab.
For 8: Open the Lenovo Support program and click Battery Health, or open the Lenovo Settings program and click Power.
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 backup battery
To check the backup battery, do the following:
1. Disable the built-in battery. See “Disabling the built-in battery” on page 54.
2. Remove the backup battery. See “1080 Backup battery” on page 64.
3. Measure the voltage of the backup battery. See the following illustration.
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

LG 52LG50FD, 52LG50FD-SA-Service adjustments-service mode entry-white balance adjustment-ADC component 1 RGB adjustment and more

  These adjustments are similar to 42LB7DF Because this is not a hot chassis, it is not necessary to use an isolation transformer. However...