Just the serial number don't help. In fact, the serial number never help here.
Can you post the brand and model? This would be MUCH more usefull.
The operating system and it's version may also offers some help if just pushing a button is not quite enough.
Some times, some buttons don't look like buttons but more like decoration...
Electro
July 2012
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix notebooks/laptop pcs.