I recently received the shock of turning on the body and seeing the message "cannot communicate with battery." This was right after I got the body back from Canon services. I called, asked what could be done, and they said (paraphrasing here) "the batteries do go bad sir."
I basically hung up on Canon I was so mad.
Thats when research mode kicked in. Some places said put the unit in to your freezer over night. Some said some sort of cleaning solution will fix it. However, I found the following video:
It worked! PRAISE JEBUS!
The only difference for me was the offending screw was in the cavity of the body. Thankfully I had a magnetic screwdriver left over from an iPhone repair. I 'fished' around in the space and found the screw further down.
For the record, all the screws that came out of the body also fit the missing screw hole. (just say'n)
