Lenovo ThinkCentre A52 Hardware Maintenance Manual page 64

1. Turn off the computer and disconnect all external devices.
2. Power-on the computer.
3. There are three LEDs to help you determine if the power supply and system
Green
Power LED diagnostic LED
ON ON
OFF OFF
OFF (after the ON
power button
has been
pressed)
ON ON
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Hardware Maintenance Manual
board are working correctly. The power button LED is located on the front of
the computer and the two diagnostic LEDs are located on the power supply at
the rear of the computer. After pressing the power button, observe the LEDs
and refer to the following table:
Yellow
diagnostic LED Action
OFF This is the normal condition of the LEDs when the power is
OK.
OFF
v Make sure the power cord is attached to a working
v Check the power cord for continuity.
v If the problem persists, replace the power supply.
OFF Replace the system board
ON Replace the power supply
If the Diagnostic LEDs are in the normal condition and the problem persists,
replace the system board and the microprocessor, one at a time, until the
computer works correctly.
electrical outlet.