How To Remove The Hard Disk Password; Power Management; Screen Blank Mode - Lenovo ThinkPad T420si Hardware Maintenance Manual

3. Remove the backup battery. For how to remove the backup battery, see "1090 Backup battery" on
page 83.
4. Turn on the computer and wait until the POST ends. After the POST ends, the password prompt does
not appear. The power-on password has been removed.
5. Reinstall the backup battery and the battery pack.
(B) If an supervisor password has been set and is known by the service technician:
1. Turn on the computer.
2. When the ThinkPad logo comes up, immediately press F1 to enter ThinkPad Setup. When power-on
password icon is appearing on the screen, enter the power-on password.
3. Select Security, using the cursor directional keys to move the menu.
4. Select Password.
5. Select Power-On Password.
6. Type the current supervisor password in the Enter Current Password field. then leave the Enter
New Password field blank, and press Enter twice.
7. In the Changes have been saved window, press Enter.
8. Press F10; then, in the Setup confirmation window, select Yes.

How to remove the hard disk password

Attention: If User only mode is selected and the user hard disk password has been forgotten and cannot
be made available to the service technician, neither Lenovo nor Lenovo authorized service technicians
provide any services to reset the user hard disk passwords or to recover data from the hard disk drive. The
hard disk drive can be replaced for a scheduled fee.
To remove a user hard disk password that has been forgotten, when the supervisor password and the 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 ThinkPad Setup. When power-on
password icon is appearing on the screen, enter the power-on password.
3. Select Security, using the cursor directional keys to move the menu.
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. Select Yes in the Setup Configuration window. Both user hard disk password and master hard disk
password will have been removed.

Power management

To reduce power consumption, the computer has three power management modes: screen blank, sleep
(standby in Windows XP), and hibernation.

Screen blank mode

If the time set on the "Turn off monitor" timer in the operating system expires, the LCD backlight turns off.
To put the computer into screen blank mode, do as follows:
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Hardware Maintenance Manual