Chapter 7. Troubleshooting And Diagnostics; Basic Troubleshooting - Lenovo ThinkCentre M79 User Manual

Chapter 7. Troubleshooting and diagnostics

This chapter provides information about diagnosing and troubleshooting computer problems. If your
computer problem is not described here, see Chapter 10 "Getting information, help, and service" on page
113 for additional troubleshooting resources.

Basic troubleshooting

The following table provides some basic instructions to help you troubleshoot your computer problems.
Note: If you cannot correct the problem, have the computer serviced. For a list of service and support
telephone numbers, refer to the Safety, Warranty, and Setup Guide that comes with your computer or go to
the Lenovo Support Web site at:
http://www.lenovo.com/support/phone
Symptom
The computer does not start
when you press the power
button.
The monitor screen is blank.
The keyboard does not work.
The mouse does not work.
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Ensure that:
• The power cord is correctly connected to the rear of the computer and to a
working electrical outlet.
• If your computer has a secondary power switch on the rear of the computer,
ensure that it is switched on.
• The power indicator on the front of the computer is on.
• The computer voltage matches the voltage available at the electrical outlet for
your country or region.
Ensure that:
• The monitor signal cable is correctly connected to the monitor and to the
appropriate monitor connector on the computer.
• The monitor power cord is correctly connected to the monitor and to a working
electrical outlet.
• The monitor is turned on and the brightness and contrast is set correctly.
• The computer voltage matches the voltage available at the electrical outlet for
your country or region.
• If your computer has a discrete graphics card installed, be sure to use a monitor
connector on the discrete graphics card.
Ensure that:
• The computer is turned on.
• The keyboard is securely connected to a PS/2 keyboard connector or a USB
connector on the computer.
• No keys are stuck.
Ensure that:
• The computer is turned on.
• The mouse is securely connected to a PS/2 mouse connector or a USB
connector on the computer.
• The mouse is clean. Refer to "Optical mouse" on page 42 for further information.
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