Anyone proficient with PS3 repair?

Here's the deal, I have an old MGS4 80gig PS3. I got it because I wanted the backwards compatibility with PS2 (my PS2 has been nearly broken for years). Anyways, a few months ago it stopped reading discs. I did all the basic troubleshooting and not getting any results and not able to afford repairs from Sony I decided to do the only other thing I could think of, opening it up and cleaning the laser. I did this exactly as tutorials showed me how and I put it back together, still no results. I've done this so many times. I'm out of ideas, is there anything I can do that would be cheap or easy to fix this problem? I'd rather not get a new PS3 (I don't like the style of the slims and I need the Backwards Compat now for many of my saves are on the hard drive).