Loud Beep when Booting my MacBook Pro

[jusacruiser]

Today, when I started my MBP I heard a loud Beep. What could that be?
😕

 

[simsaladimbamba]

Power-On Self-Test Beep Definition - Part 2
http://www.google.co.uk/search?q=apple mac beep&ie=utf-8&oe=utf-8

 

[jusacruiser]

Power-On Self-Test Beep Definition - Part 2
http://www.google.co.uk/search?q=apple mac beep&ie=utf-8&oe=utf-8

Ok, I will do that.....OR.....I also have a tech disc from AppleCare. It is supposed to determine the health of your Mac. Do you know anything about the AppleCare tech disc?