OptiPlex 5250 All In One Beep Codes and Diagnostic Lights

Hi,

Recent OptiPlex 5250 All In One, was in Powersave, screen blank, with the LED light on the lower right hand corner blinking red in a 3 blink - pause - 2 blink (or was it 2 blink - pause - 3 blink?) pattern.

Questions:

1) What does this mean?

2) I'm a technician, and what I would do for any computer is consult the service or owner's manual. But much to my surprise, the owner's manual for this model does not have documentation for the beep codes or diagnostic lights!

It says on Page 67, "You can troubleshoot your computer using indicators like diagnostic lights, beep codes...".

Well, yes... if you know what they mean.

Where is the documentation for beep codes and diagnostic lights for the OptiPlex 5250?

Thanks.