Well - v4 ps2's and down are the ones with weak lasers. HOWEVER! - you COULD have a version 4 even though that model number is for a v5 (this happened to me). Your best bet is just to swap for a refurbished. Make sure you know the model number first. Settle for nothing less than a v7.
Good news. I went to EB yesterday and here's the deal - I get 100 dollars in store credit if I trade in my Playstation (broken even), its cords, and a controller. Seeing as how my brother was able to get numerous controllers when working at KB, there is no problem. I'll buy a BRAND new PS2, for only 40 dollars (splitting with my bro).