my mac is not turning on at all and it does a beeping sound instead

Hi there, I had some problem with my macbook pro a while back, in which the screen was getting blank/frozen and I had to force quit it, and when i tried to turn it back on, it started beeping and would not turn on...then I would wait some hours and it would finally turn on. It was acting like this for a while and I managed to fix it by repairing the disk in disk utility and it was working fine...

Now, since yesterday, it started again, and i had to force quit it, but this time, it is not turning on at all anymore, and it only does the beeping sound when I try to turn it on...firts it does one beeping at a time, and then I force quit it again and turn it on again and it does a faster beeping sequence.

Can anyone help me?

my mac info is:

Mac OS X

version 10.6.8

2.4 GHz Intel Core 2 Duo

4 GB 1067 Mhz DDR3

I never did any work on it, never changed anything...it is just like I got it from the shop.

Thanks

Check the beep codes to decipher what the issue might be to start with - link

Just a guess, but I'd be willing to bet the memory modules need to be re-seated - particularly if the machine was jostled or dropped at some point before the beeping started.

I opened it , took the memory cards out and placed them back on...seems like the plastic device that is supposed to hold the card in place is not working properly, so with a help from a friend, we fixed it so that the card would be safely in place...and so far it is working again.
yes!!!
But will be under observation.
Meanwhile, doing all my backups.
thanks...