I have a 15" MBP from around 2006, the one where they first introduced the new magsafe connecters. It's started to make a rattling noise which is very rythmic leading me to believe its the fans. Several years ago it started to make a clicking noise but that stopped and until recently it's been fine. If it is the bearings on the fans or something like that, how much would that cost to fix? The machine is well out of warranty now.