GitHub - enthdegree/f100

Nikon F100 Notes I repaired a Nikon F100 film camera sold for-parts. For my camera, an internal cleaning was all that was actually needed to get it working. Unfortunately, for lack of documentation and knowledge I created a lot more work for myself than was necessary. Here is what I wish I knew before starting. Preliminaries Documentation The Nikon F100 repair manual and parts list are necessary but not sufficient. They are terse, vague and narrow in scope. Copies circulating online are low-quality scans. Afotandovy has some useful disassembly photographs and comments: https://afotandovoy.blogspot.com/2013/02/reparacion-nikon-f100.html If I could go back in time I would urge several points to past-me: Read Richard Haw’s brief general camera repair fundamentals articles https://richardhaw.com/lens-camera-repair-fundamentals/ Forcing things when I should have taken a break led to unnecessary damage that was difficult to repair Almost the instant you take off each tiny screw you will drop it on the floor and forget the hole it came out of. 
Come up with some system to defend against these things. 
Many of the screws look near-identical and almost none of them are interchangeable. 
Pill tray systems will get knocked over and you will mix up the compartments. 
I should have disassembled everything over a magnetic screw mat, and sorted screws according to their names from the repair manual. If I had known how annoying everything was to clean before reassembly I would have worn disposable gloves for everything. Common tools JIS 0 screwdrivers. iFixIt Minnow has JIS-compatible ones. Fine tweezers Rocket blower Cleaning materials: Coffee filters Microfibre cloth Toothpicks and Q-tips Cleaning chemicals: Distilled water 99% Isopropyl alcohol (be really limited with using this on the polycarbonate body as it makes it brittle) white vinegar (not for use on the polycarbonate body but rather for cleaning rust for metal parts that were removed from it) acetone (turns the internal polycarbonate body into mush instantly on contact. essentially destructive. extremely limited applicability if any. only thing I’d use it for is as a last resort for extremely tight screws, applied with a toothpick) Strong double-sided tape. I used Scotch 9495LE. Soldering iron (to get some delicate ground wires off without damage) Box of 100 nitride gloves A lot of for-parts F100s on sale already have some essential components gutted. This makes the economics of repairing them pretty bad. Here are common missing parts I noticed, together with replacement status: Eyepiece The standard is Nikon Viewfinder Eyepiece 2927. Ebay price is $25. It is a very simple part. Metal aftermarket versions are currently manufactured and cost $12 shipped. The ring for the F100 seems to have dimensions close or identical to the Nikon DK-17 (for which free replacement models are published), but I haven’t yet found empirical evidence they are interchangeable. You’d still need to find a glass window for those too. Battery cartridge The standard is Nikon MS-12 (4xAA batteries). Ebay price exceeds $100 which is obscene. Bogdanbogvzyan sells compatible design files for $10 at Cults3D: https://cults3d.com/en/3d-model/gadget/nikon-ms-12-aa-battery-holder-for-f100 . 3D prints of that can be found for $30 shipped. I attempted to print that design with PLA (Thank you HackManhattan) but it failed during assembly due to layer separation and the screws sheared out of their holes. If I tried printing it again, against the designer's recommendation I’d print it on its side instead of vetically. The standard is Nikon Type B Focusing Screen 2599. Ebay price is $28. No easy way to roll your own fresnel lens as far as I know. I don’t know why ground glass of the right thickness wouldn’t work OK. Dimensions in Figure 1. Film door The assembly is 1B999-938 in the parts list. Replacements sell for $100 which is obscene. The latch hooks frequently fail and a simple repair jig + metal hook kit can be bought for $20 which seems reasonable. The whole film door is actually a simple passive electromechanical part that would be feasible (if a bit complex) to fully remanufacture, if/when it becomes economical to do so. I don’t have the expertise to do this, though. Figure 1: F100 focus screen dimensions. Numbers are mm. Symptoms out of the box My broken F100 came without the eyepiece and its battery cartridge was shattered. The seller said this camera died from battery corrosion. By the time they cleaned the battery compartment the corrosion had already corrupted the inside of the camera. Its behavior was erratic: Typically the camera would appear totally dead. Sometimes putting batteries in, the LCD would show garbage, sometimes fading out. Rarely the camera would turn on and show the low battery indicator. No function or button worked in this state. If you pushed any button here the indicator would start blinking. Very rarely inserting the batteries would power up the camera into an ostensibly-working state for a minute or so. Here the shutter would behave like it was being held down forever after its first press, until a power-cycle. Shutter releases 1/2000 and faster would usually misfire and show Err. The batteries would sometimes heat up quickly. Scary. As soon as I noticed this I stopped testing. Disassembly and cleanup Corrosion was visible at the seams around the battery compartment/grip. The top cover, baseplate and grip had to be removed to expose the contaminants that had leaked into the body. I followed the “Disassembly 1. Exterior" section of the F100 repair manual. Also helpful are the afotandovy photographs up to and not including removal of the LCD screen’s screws. Fine points of disassembly: There is an FPC connecting the top cover to the camera body under the side opposite the LCD. It is easy to rip if you don’t know it’s there. To remove the top cover safely I lifted it off lift it off as pictured in Figure 2. You have to lift the cover off with one hand and unscrew the two retainer screws with the other. The metal grip/battery compartment is electrically grounded with a copper clip retained by one of the screws. A blue wire is soldered onto that clip, and the wire’s opposite end leads to some FPC deep inside the body. I desoldered the wire from the clip to avoid the wire snapping during grip removal. The wire and clip is visible in Figure 3, circled in white. Figure 2: Top Cover removal, FPC in red. Contrary to the illustration the film door/rear cover is probably off the camera at this point. Figure 3: F100 grip ground clip, soldered onto a blue wire. I desoldered this during disassembly for cleaning and safe handling. Corrosion cleanup for all the electronics followed the same pattern: Flaked off what corrosion I could see with a toothpick Wiped with water to dissolve the rest of the corrosion Final wipe with isopropyl alcohol all the while blasting air at it with a rocket blower Much of the contamination was almost-completely invisible: There was contamination around the power FPC ribbon. Something around here was the plausibly cause for symptom 1. See Figure 4, red arrow. A window at the ceiling of the battery compartment exposes a spring-loaded contact. Normally a peg on the MS-12 battery cartridge pushes the switch open, indicating to the body that 4xAA power is expected. A plausible explanation for symptom 2 is that corrosion kept this switch shorted, thus the body expected a higher voltage. See Figure 4, white arrow. Buttons on the top cover signal depression to the body by shorting a radial pad on the FPC to a ground rail. Symptom 3 was due to contaminants shorting the shutter switch closed around some contact arms. See Figures 5a and 5b. Separately, removing the metal grip revealed rust-red corrosion that I cleaned off with white vinegar, rinsing thoroughly with water afterwards. Figure 4: Power FPC with corrosion. The white arrow points to the MS-12 indicator spring-loaded contact. The red arrow points to an FPC area. Besides the obvious green corrosion around their edges both seemed otherwise clean. They weren't. Symptoms did not resolve until thorough cleaning. Both sides of the spring-loaded contact and the surrounding FPC extend fairly deep into the camera’s interior. Those areas had to be reached carefully with a toothpick saturated with distilled water, then isopropyl alcohol the same way. It was sufficient to reach them this way rather than through more disassembly. Figure 5a: F100 shutter spring contacts inside the top cover, above the front dial. There are 3 prongs in a stack around the white arrow. Flecks of some contaminant visible on the base prong. You need a toothpick saturated in cleaning material to get close to the base of each prong. I could only detect the cleaning was effective by measuring the shutter-to-ground ‘open’ resistance slowly climb on the multimeter up from 7 kOhm pre-cleaning (see Figure 5b). Figure 5b: F100 top cover FPC radial pads used for communicating button state to the body. Button depression is supposed to short each of those pads to a ground rail. Ground is electrically connected to some other exposed metal which is a more convenient measurement point. ..and then everything is supposed to go back on the way it came off. The grip rubber and diopter cover need new double-sided tape. It could’ve been that simple… Addressing damage caused during disassembly (The Odyssey) Stripped screw During disassembly I stripped the head of a stuck screw. Richard Haw, linked above, has advice on this. I managed to remove it with a dot of white vinegar and a lot of friction. Of course you don’t know what screw you need until it is lost or destroyed. If you are lucky the screw is one that came in a pair so a twin is available for measurements.