Bootable Diagnostic Programs - ThinkPad T420 Hardware Maintenance Manual

1. Turn on the computer. If the computer cannot be turned on, go to "Power system checkout" on page 37,
and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on page 47
for error code descriptions and troubleshooting hints.
2. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot Menu
window opens, release the F12 key.
3. Press the Tab key to switch to the Application Menu window.
4. Use the arrow keys to select Lenovo Diagnostics and then press Enter. The main screen of the UEFI
diagnostic program is displayed.
5. Follow the instructions on the screen to use the diagnostic program.
The options on the main screen are as follows:
• Quick Memory Test
• Quick Storage Device Test
• Exit Application

Bootable diagnostic programs

If the computer you are servicing is not installed with the UEFI diagnostic program, you can download a
bootable diagnostic program from the Lenovo Support Web site. The bootable diagnostic programs enable
you to test computer memory and internal storage devices, view system information, and check and recover
the internal storage devices. To use the bootable diagnostic programs, you can create a bootable diagnostic
medium on a USB device or CD.
To create a bootable diagnostic medium, do the following:
1. Go to http://www.lenovo.com/diags.
2. Click Lenovo Bootable Diagnostics.
3. Follow the instructions on the Web site to create a bootable diagnostic medium on a USB device or CD.
To use the diagnostic medium you have created, do one of the following:
• If you have created the bootable diagnostic medium on a USB device, do the following:
1. Attach the USB device to the computer.
2. Turn on the computer. If the computer cannot be turned on, go to "Power system checkout" on page
37, and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on
page 47 for error code descriptions and troubleshooting hints.
3. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot
Menu window opens, release the F12 key.
4. Use the arrow keys to select USB HDD and then press Enter. The diagnostic program will be
launched automatically.
5. Follow the instructions on the screen to use the diagnostic program.
• If you have created the bootable diagnostic medium on a CD, do the following:
1. Turn on the computer. If the computer cannot be turned on, go to "Power system checkout" on page
37, and check the power sources. If an error code is displayed, go to "Symptom-to-FRU index" on
page 47 for error code descriptions and troubleshooting hints.
2. Insert the CD into the optical drive.
3. Restart the computer.
4. When the ThinkPad logo is displayed, repeatedly press and release the F12 key. When the Boot
Menu window opens, release the F12 key.
Downloaded from LpManual.com Manuals
Tests Tools
• System Information
• Recover Bad Sectors Tool
Chapter 3
. 35
General checkout