I have a tg3 as a backup camera. It locked up in little cayman so I bought a tg4 and kept the tg3 as a backup. I never had a problem with the 3 again until last week and it locked up again, at first the camera would come on but nothing would work (could not change any settings or see thru the lens). I tried turning it off, remove battery but no change. Then I tried changing the setting from auto to underwater, it then allowed me to see thru the lens but nothing elserious. Next time I turned it on it worked fine. Any thoughts? Is it worth sending in to be looked at? If I do and it's working how can they determine a problem.