Only one, my fat PS3, fan always sounded loud, but towards the end it was ridiculous. Getting a super slim for far less with almost 10x the storage made the loss sting less.
To be fair though, I'm sure my old PS1 & PS2 no longer work, wherever they are. I beat the shit outta my PS1, and my original PS2 was acting up right before I gave it away when I got my PS3.