My F100 locked up yesterday -- frozen tighter than a banker's wallet. This was the second lock-up in about six weeks of ownership. The first was about three weeks ago. But I believe I've found the cause and cure, and perhaps a solution to the early-rewind syndrome. About three weeks ago I was out shooting on a nice day, and as soon as I took a shot of a seagull staring at me from its perch on a dock the F100 froze -- mirror locked up, all of the LCDs were blank, and nothing worked. The batteries were not _new_ but should have had adequate life left. I turned the power switch on and off a couple times with no good results. I took out the battery clip and replaced it. Still no good. About five minutes passed. I turned the power on again. This time the camera came to life and I was able to finish the roll and rewind. The battery life indicator now said the batteries were dead, so I replaced them and the camera worked fine the rest of the day. My wife was attending the Nikon School that day. When I went to meet her at the end of the day, I mentioned the lock-up to one of the Nikon tech reps who was there. He seemed concerned, almost as if he had heard of it before, and told me to monitor the problem and send in the camera if it happened again. I also told him it might have been marginal batteries, and turning off the camera for five minutes or so might have allowed them to recover enough to finish the roll. He agreed that could happen. Yesterday I was out shooting the obligatory cherry blossoms (I'm in the Washington, D.C. area). After a few shots the F100 froze again. This time the mirror was down, and all the LCDs showed the previous settings. None of the buttons worked. Command dials turned but didn't affect anything. Power on/off did nothing to clear the situation. Batteries were practically brand new, and this time I had the MB-15 attached, so power should not have been a problem. Then I removed the battery clip from the MB-15, put it back, turned the camera on, and everything worked fine. Here's what happened in both cases, which I believe caused the problem. The manual specifically says "Make sure to turn the main switch off when attaching/detaching the lens" (page 19 of the manual). Normally I do. But in both of the lock-ups I changed lenses _with the power turned on_! In yesterday's case, I also changed back to an AF-D lens from my trusty manual, non-AF (but AI) 105 f/2.5. My theory is this somehow confuses the camera's computer, and it locks up requiring the equivalent of a personal computer reboot. (Taking out the batteries essentially resets the entire system.) I've had the exact same thing happen with my wife's N60, so I think it's a function of the system. Not a bug, not a feature, but just a fact of life. About early rewind. Haven't had it happen on the F100, but it has happened with the N60. And with the N60 I've also seen skipped frames (mostly at the start of a roll -- an exposure or two, then several blank frames, then normal exposures to the end.) This proved to be the result of loading film _with the power switch OFF_. (Again, the manuals specifically say to turn the power on when loading film -- the film will load fine with power off, but probably the computer again gets confused when the power is turned on and doesn't accurately count frames.) Of course, tight film could also cause early rewind if the tension fooled the camera into thinking the end of the roll was reached. (An aside -- there's been some talk on the Canon EOS list that some Canon models are hardwired to initiate rewind after 36 exposures no matter how much film is left in the canister.) So to summarize a long post. MAKE SURE to turn power ON when loading film, and power OFF when changing lenses. Any other thoughts also appreciated. -- John Albino mailto:[EMAIL PROTECTED]
