Post count: 246

The focus problem is most likely due to a common problem with the 300D. There is a sub-mirror needed for focusing, that moves in synch with the main mirror. This movement is controlled by a plastic pin that tends to break off causing the problem you’re having. There are many articles on this problem on the net and this Google search will give you a good place to start investigating. There is a well documented repair that you can do yourself if you’re confident enough to dismantle and reassemble a fairly large part of the camera. The repair itself is pretty much guaranteed but the danger lies in your breaking something else. I don’t know how much an authorised repair centre would charge for this repair.