MacBook Pro will not start

Hi all. My MacBook Pro has decided to not start up anymore. When the power button is pressed, there's a little sound & the power light in the front comes on but the fan never starts up & it never makes that beautiful startup sound I so want to hear. When I was able to use it prior, it did shut down a couple of times unexpectedly, however the battery indicator had still shown that it had some charge left. Any suggestions? As of now, I can't even get it to power up.
Thank you.