I don't have an answer for the OP, sadly, but I just wanted to clear up a few misunderstandings in the replies. There are no limits to how many times you can download your PSN purchases; the only limitation is that you can only have two systems activated, or valid, to use them at a given time (five systems, if the purchase was made prior to 2012, I think, or whenever it was that they changed the policy; it only affected new purchases made after that date). Even if your system dies, as long as you have an internet connection, you can go to Playstation.com, and log in with your PSN account and deactivate the system; the only catch is, it will deactivate all systems, so if you have another one, you'll have to reactivate it, which is a simply two-minute event.
Again, after the fact, but with the older PS3 systems, I recommend taking advantage of the back-up tool under System Tools, and backing up your data on a regular basis. It will even copy over non-copy-able files, and you can restore it to another hard drive (it will, however, format the hard drive it's restored to, so make sure you do this to a fresh one).
Check with any local non-GameStop used game stores around your area, as well as look up Game Repair Services online, some of them may do system repairs. I would recommend only using this as a temporary measure though; once the yellow light occurs, it will occur again, with almost no exception. The repair will be good enough to use the back-up tool, or if you have a new system available quickly, there is the nice transfer tool as well. But trust me, don't consider it fixed for good. My poor original 60GB went through three seperate yellow lights before I finally retired it, first with BlazBlue Calamity Trigger, with the second occurring two months later (Star Ocean... and less than two weeks before FFXIII), and the third about six-seven months after that (honestly, no idea what I was doing; it simply yellow lighted one morning, after I had been playing something the night before).
On the plus side, the newer slims and super-slims are almost universally better, unless you just can't live without PS2 games. And that nice white super-slim is dropping at the end of the month...