First, try putting the console in [http://community.us.playstation.com/t5/PlayStation-3-Support/How-to-access-the-PlayStation-3-Recovery-Menu/td-p/19195118|recovery mode] and running the "Restore File System" option. If you are met with errors here, the hard drive may have failed/is failing. PS3's store a portion of their operating system on the hard drive and the fact that the problem got worse to the point where it wouldn't boot up suggests this. You can confirm it a number of ways. The easiest is probably to put your ear up to the console when turning it on and listening for a [https://www.youtube.com/watch?v=YqgkqcNCrj8|faint clicking sound like the one in this video at around 10 seconds]. That's a definite sign that the hard drive is dead. If you can't hear anything and happen to have one laying around, put the drive in a SATA hard drive enclosure, connect it to a computer, and test it in there (However, a PC will not be able to detect the drive without formatting, which will delete all data on the drive if it still works, so ignore any prompts to format the drive if you test it with this method). If it turns out that the hard drive is the problem, you can order any 2.5" SATA hard drive as a replacement and install it with [guide|3476|this guide] assuming you have a fat PS3 (Shaped like the one in the iFixit picture)