This is the first thing that you should do. Perform a power reset and see if it works for you. Some laptops have a power reset button. If your laptop has such a button, use it to perform a power reset ...
Your computer checks all installed components when you attempt to boot, and it offers a code when it detects a problem. This code could be a series of beeps or LED ...
So, I was working on my Dell D600 last night when it completely froze on me. Forcing a power down by holding the power key and then trying to boot up again yielded nothing but a flashing CAPS lock key ...