This may be a broken-camera problem and not a CHDK issue. Yes I did originally want CHDK for its features but now I am hoping it can somehow solve the problem by wiping the firmware to zero or whatever. The problem existed before I ever installed CHDK.
The lens is permanently stuck open and I get the message "Lens Error. Will shut down automatically. Restart camera."
Shooting Mode is completely dead but Playback Mode works fine (menus and options; before reformatting I was able to photos on the card).
*After* the problem started I successfully installed CHDK using STICK and locking the SD card. I get the CHDK startup logo and can get to the CHDK menus and navigate around so it appears to be OK.
I downloaded new firmware and installation instructions from the Canon site but there's no Firm Update option in the menu and without that, I don't see how I can update the firmware.
The camera was not dropped, hit or near dirt or sand. I don't know if normal everyday microscopic dust is capable of getting in and wrecking the entire motor!?