You could try blowing some compressed air into the area around the switch and see if it helps.
Otherwise, it's most likely the cord or the switch.
Can you check to see that you actually have power to the switch. If yes, and you feel adventurous, then first remove the blade, then bypass the switch, (using a power strip as a cord switch) to check to see that the motor works, in which case it must be the switch...they do go out.
Here's a link to parts for your saw: http://www.makita.com/en-us/Assets/images/Products/_PartsBreakdowns/PB_LS1013F.pdf
I hope this helps you to resolve this problem. If there's anything more I can do to help, please don't hesitate to write back...
If I've managed to answer your question or solve a problem, please take a moment to kindly rate this post....thanks!