Power supply and system board Diagnostic LEDs
You computer has two LEDs located on power supply on the back of the
chassis. The power button LED located on front of your computer and the two
LEDs on the back will help you determine if the power supply or system
board is working correctly. The following table uses the LEDs to diagnose
possible power supply and system board problems.
Power Button
LED Green LED Yellow LED Diagnosis
Off Off Off Check the following first:
v Is power cord plugged in?
v Is the power strip on?
Failing power supply
Off (After
pressing the
power
button)
On Off Failing system board
On On On Failing power supply
On On Off Normal working conditions, but if your
computer is not working correctly then you
have a failing system board or a failing
microprocessor
If you cannot correct the problem, have your computer serviced.
Note: To reset the computer once a yellow LED is on, unplug the power cord.
PC-Doctor for DOS Diagnostics
The PC-Doctor for DOS Diagnostics program runs independently of the
operating system. You can use this program to test hardware components of
your computer. You can use this program when other methods are not
available or have not been successful in isolating a possible hardware problem.
You can run the diagnostics from the Rescue and Recovery workspace on your
hard disk. Alternatively, you can create bootable diagnostics diskettes from the
Rescue and Recovery workspace.
You can also download the latest version of the diagnostics program from
http://www.lenovo.com/think/support/ on the World Wide Web. Type your
machine type and model number into the Quick Path field to find the
downloadable files that are specific to your computer.