There is no way to fix this problem other than to send it to Canon. I have had to send my G30 and G40 in a total of 3 times to have that zoom problem fixed. the last time it cost $400.
I bought a G30 several years ago. Within a year the zoom out problem began. I sent it in and Canon fixed it for free. It happened again a year later Canon fixed it again but not for free. To preserve my G30 I used it mostly with remote thumb control....
I could not find another camcorder as good, as small, and as cheap as the G30-G40. Suggestions? What I particularly like about my G30 is the zoom rocker on the side. Most similar units have a useless zoom control on the top. There is no better camcor...