Recently got a 10" Meade LX200 GPS SMT and find the focus lock doesn't really work. Firstly it's difficult to turn, at some points needing two sets of fingers to do so. Secondly it never really locks the mirror though the focus knob gets a bit harder to turn. I've had a couple of these scopes before and the lock worked fine, easy movement of the knob until some increased resistance is felt which locked the mirror solid.
Any ideas? Not keen on the idea of removing the mirror to get at the mechanism but I will if I have to (instructions with photos or a video would make me feel more confident!).