Lenovo ThinkCentre M90t Gen 3, Hardware Maintenance Manual, Page: 45 / 104

Chapter 5. Diagnostics
Use diagnostic solutions to test hardware components and report operating-system-controlled settings that
interfere with the correct operation of your computer.
Basic procedure for resolving computer problems
Prerequisite
Before you start, read Chapter 1 “Important safety information” on page 1 and print the following
instructions.
1. Check that:
a. The cables for all connected devices are connected correctly and securely.
b. All components have been reassembled correctly.
c. All connected devices that require ac power are connected to properly grounded and working
electrical outlets.
d. All connected devices are enabled in UEFI BIOS.
2. Use an antivirus program to see if the computer has been infected by a virus. If the program detects a
virus, remove the virus.
3. Go to “Self-help resources” on page 40 and follow the instructions for the type of problem you are
experiencing.
4. Run the diagnostic program.
5. Recover your operating system. See “Self-help resources” on page 40.
6. If the problem persists, contact Lenovo.
UEFI diagnostic program
A UEFI diagnostic program is preinstalled on the computer. It enables you to test memory modules and
internal storage devices, view system information, and check and recover bad sectors on internal storage
devices.
To run the UEFI diagnostic program, do the following:
1. Turn on the computer. If the computer cannot be turned on, go to “Basic procedure for resolving
computer problems” on page 39. If an error code is displayed, go to “Symptom-to-FRU index” on page
32 for error code descriptions and troubleshooting hints.
2. Repeatedly press and release the F10 key when turning on the computer. The main screen of the UEFI
diagnostic program is displayed.
3. Follow the instructions on the screen to use the diagnostic program.
The options on the main screen are as follows:
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