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Image 1 — Update on my DIY shutter tester project
Image 2 — Update on my DIY shutter tester project
Image 3 — Update on my DIY shutter tester project
Image 4 — Update on my DIY shutter tester project
Image 5 — Update on my DIY shutter tester project
▲ 9 r/filmcamerarepair+2 crossposts

Update on my DIY shutter tester project

Hi everyone,
I posted months ago about my DIY open source uShutter project.
I’m sharing an update on it after such a long time.

I’m still actively improving the design including the communication module between the device and computer, and firmware upgrading module. And would really appreciate feedback from people who repair, test, or build camera equipment.

More details are at https://ushutter90.wordpress.com
Source code and PCB files are open to download at GitHub: https://github.com/ushutter/uShutterUp

u/C41lightleak — 7 hours ago
▲ 27 r/filmcamerarepair+1 crossposts

Canon A-1: Repair and overhaul Finale

Hello friends of tiny screws and frustration tolerance,

EDIT: Deleted and reposted since a picture was not displaying right

here is finally the third and last update to the A-1 restoration project, my first experience with camera repair and CLA.

Part I
Part II

Last time I left you with the completed CLA and the lessons I learned along the way. This time I will address the two leftover tasks/problems:

  1. The viewfinder display being extremely dim (almost invisible to the naked eye), and was missing the G segment on all the individual displays.
  2. Since disassembling the camera implies pulling the leatherette, I wanted to re-leather the camera in a colour. After all the work done, I didn't want it to look like a stock A-1 :)

To start tackling the viewfinder display problem, I first resorted to the repair manual. The 7-segment miniature displays are controlled by a BCD decoder/driver IC, which in this case is a custom part from Canon. The only advice from the manual to change the brightness of the display is to modify a resistor, RIADJ, which configures the internal constant current source of the IC. Since this is a carbon resistor, I suspected (and hoped) that it had drifted upwards with age, but that was not the case. The resistor is an E96-series 3kOhm, and measured almost bang on. I also tested a 47uF decoupling tantalum capacitor that is right next to the IC, but the capacitance too was well withing tolerance. Bummer!

The BCD decoder IC also provides a trigger function for multiplexing not only the displays, but also several buttons and inputs to the camera. To prevent backcurrents during multiplexing, a large diode array is used. However, a failure of a diode in the array would not explain the missing G segment, since they control if a whole display lights up and not the individual segments, which is controlled by the BCD decoder itself. The probable cause would then be an output stage transistor in the IC not working.

Nevertheless, I wanted to experiment before I gave up with that intensity resistor. I replaced RIADJ with a 5k trimmer to vary the resistance and see how it affects the brightness. So, with a half-pressed shutter pushrod and a very uncomfortable position I looked through the viewfinder. Imagine how underwhelming it was to see absolutely nothing change when varying the resistance! This was enough to determine that the IC was at fault.

An interesting observation is that, when I tried the trimmer with the long cables I show in the picture, the camera acted weird. I tried firing the camera, but the curtains would hang often and randomly. Only after I shortened the wires it started acting normal again.

Luckily, the display unit is a flex PCB module which contains the display, the IC and the resistor and capacitor and can be easily exchanged. Although the module is mounted through press-fit connectors, desoldering some wires is necessary to remove it. I got a replacement module from eBay, which gave me a nice, bright display again, and a living G segment.

To crown this project, I decided to get some fake leather and make the camera look a bit different. I edited a picture of the camera to cut off the original leather and replaced it with pictures of different self-adhesive leathers I found online to see which one I liked the most. After bothering all of my friends for their opinion, I decided to go with a burgundy one I found in Amazon. It turned out to be quite thick (almost a mm), while the original leatherette of the A-1 is around 0.5mm thick. Nevertheless, I drew the cut template by scanning the original leatherette in a flatbed scanner and drew it in CAD. Then cut the leatherette with a laser cutter, painted the cut edges black with an edding and glued it on the camera. All in all it looks quite good, and the thickness difference is not that noticeable in my opinion.

Thank you for reading! It was a cool adventure. I am definitely hooked on camera repair now!

u/OkBattle5479 — 2 days ago
▲ 29 r/filmcamerarepair+1 crossposts

Lesson 1 Canon AE-1: Cleaning the Magnets

https://preview.redd.it/3xoj208tu6ah1.jpg?width=4032&format=pjpg&auto=webp&s=d5d0d949478e40f9372db6a1593a8a4e98540838

Lesson 1 Canon AE-1: Cleaning the Magnets

Often, when you use a Canon AE-1 after a long time and insert a new battery, you’ll notice that the shutter is stuck. This can obviously be caused by various factors, but one of the most common is undoubtedly dirt on the MG2 and MG3 magnets located on the bottom of the camera.

https://preview.redd.it/gicdtizuu6ah1.jpg?width=4032&format=pjpg&auto=webp&s=d0abf124420adce03c80942c8574a981c607d62f

From *The Camera Craftsman* Manual:

  1. MG2 – Release Electromagnet
  • Holds the armature locked during shutter cocking.
  • When you press the shutter release button, the circuit discharges a capacitor through the MG2 coil.
  • This pulse temporarily cancels the permanent magnetism.
  • The armature is released, allowing the mirror and shutter to begin moving.

➡️ MG2 initiates the shutter release.

If MG2 malfunctions--> You press the button but nothing happens or the shutter remains stuck.

  1. MG3 – Second Curtain Electromagnet

After MG2 has initiated the shutter release:

  • MG3 holds the second shutter curtain in place.
  • The electronic circuit keeps it energized for the set duration (1 s, 1/60, 1/1000, etc.).
  • When the electronic timer cuts off the power, MG3 releases the second shutter curtain, ending the exposure.

In practice:

➡️ MG3 determines the exposure duration.

If MG3 isn’t working:

* the second curtain fires immediately → incorrect exposure times;

* or it remains held → shutter stuck open.

FROM THE CAMERA CRAFTSMAN MANUAL:

https://preview.redd.it/yog32hlxu6ah1.jpg?width=643&format=pjpg&auto=webp&s=8b7d7a69b59d11dde1c0f4b893eaaa17f2e0b0f3

First, check the mechanical release mechanism: simply use a screwdriver to push the MG2 armature toward the front of the camera. The shutter should fire.

If the shutter fires, you know there is no mechanical problem.

So the problem could be:

  • a broken MG2 coil (open coil);
  • or a faulty capacitor—that is, the capacitor that discharges current through the coil to neutralize the permanent magnet.

You can check both the coil and the capacitor at the same time.

Wind the shutter. Then use tweezers to short the negative terminal of the MG2 coil to ground (the edge of the camera body or the ground screw on the flexible circuit board).

https://preview.redd.it/fbzzwdnzu6ah1.jpg?width=879&format=pjpg&auto=webp&s=adf6af4d732c4629ec4129cda9d26583bb95188b

The armature should detach from the MG2 core and release the mirror.

This test bypasses the electronic switch that normally sends the current pulse to the MG2 coil.

Remember that capacitor C47 (47 μF) is connected in series with the MG2 coil.

When the electronic switch closes, it allows capacitor C47 to discharge through the MG2 coil.

If shorting the switch does not release the shutter, check that power is reaching the flexible circuit board. Locate the red wire running from the flexible circuit to the MG3 solenoid. This red wire connects the flexible circuit to the positive terminal of the battery. When measuring the voltage between the red wire and ground, you should read the full battery voltage (approximately 6.35 V with no current draw). Similarly, you can check the voltage at each terminal of the MG2 solenoid. You should measure the full battery voltage at each terminal. If you find it, it means the coil is not open.

Now let’s assume that the short-circuit test does not trigger the shutter.

However, you have measured the correct voltage on the flexible circuit board.

At this point, the question remains as to whether the faulty component is:

  • the coil;
  • or the capacitor.

You can replace:

  • the entire electromagnet;
  • or capacitor C47, located at the bottom of the camera.

To check whether the magnets are functioning properly, test them with a multimeter.

MG2 has a resistance of around 95 ohms;

https://preview.redd.it/3a2uq481v6ah1.jpg?width=3024&format=pjpg&auto=webp&s=9d3e5ce7780e2d4b1773609cceeab0054177668d

MG3 has a resistance of around 224 ohms.

If they don’t have the correct voltage or show zero voltage, there’s definitely a problem with the coil—the solution is to replace them.

If they’re working but the camera doesn't fire, try cleaning the contacts on the armature and magnets, because the armature might not be returning to its original position due to being stuck to the magnet by dirt that has accumulated over the years.

First, use a powerful air blower; then, make sure to wear LATEX GLOVES and proceed with PATIENCE AND CAREFULNESS—OTHERWISE, YOU’LL MAKE A MESS.

https://preview.redd.it/d0b1hph2v6ah1.jpg?width=3024&format=pjpg&auto=webp&s=5aea960f4b2fbd4b2c15d08446420cd7ad3a961a

https://preview.redd.it/dw0ihpg8v6ah1.jpg?width=3024&format=pjpg&auto=webp&s=883c612499785c31bef0d6eb13997d5d2c268345

https://preview.redd.it/ef7ddqg8v6ah1.jpg?width=3024&format=pjpg&auto=webp&s=7b6011599f325637595117873dfe8a6e076aa1f1

https://preview.redd.it/bpscnog8v6ah1.jpg?width=3024&format=pjpg&auto=webp&s=e9bb3574955888bde0f614f65e573c85e2d5197a

https://preview.redd.it/1c4nzpg8v6ah1.jpg?width=3024&format=pjpg&auto=webp&s=9c1c9beb4d8f97619ea437f42edcc9d2842ca038

To disassemble the MG2, remove the two screws and the ground screw to lift it just enough to remove the plastic cover (be careful not to break it). Then use the air blower again, this time with isopropyl alcohol or lighter fluid to remove the dirt and grease that has solidified after years and years of sitting in our closet. (Or Dad’s closet.) After that, clean the plastic cover as well, and gently reassemble everything.

Then move on to the MG3… here too, just two simple screws… clean the contacts the same way and reassemble.

https://preview.redd.it/wuqo8dpbv6ah1.jpg?width=3024&format=pjpg&auto=webp&s=ecacf5b69a4f529c9eeb56b9745c97603bd7631f

https://preview.redd.it/hwy4bdpbv6ah1.jpg?width=3024&format=pjpg&auto=webp&s=7d92a1ccb67adb6a21beb3a1c1d02f1c77f25a06

https://preview.redd.it/exh3cdpbv6ah1.jpg?width=3024&format=pjpg&auto=webp&s=4233c4db40630a18af65da43f0ea8c16f3cbb3c0

https://preview.redd.it/h4tzocpbv6ah1.jpg?width=3024&format=pjpg&auto=webp&s=223b9afaac3ff33a0b6b2fe53952633fa6147ce9

Insert a battery and test the camera. It doesn’t work? Well, I’m sorry for you, but not everything in life is that simple… there could be dozens of other problems.

You can test MG2 again by shorting it with tweezers between the positive terminal and ground. If the camera triggers this way, the problem isn’t with the magnets but with something else in the part above the camera…

A damaged flexible printed circuit board or who knows what…

If it doesn’t work when tested with tweezers, then the magnet’s resistor or capacitor C47 isn’t working. Buy a replacement part or another car :(

https://preview.redd.it/8beny1ydv6ah1.jpg?width=921&format=pjpg&auto=webp&s=2cd6249d66b56039ece85bbe6a17f90b9450f5d3

Remember that you can, of course, also measure the battery voltage across the wires connected to the MG3 magnet. One of the red wires comes directly from the battery compartment, so it’s useful to test it against ground (as well as the other red and black wires, also on MG3), and you should read the battery voltage. If you get a reading, the electrical connections are okay and the coil isn’t open. If you don’t get the correct voltage, maybe the red wire between the battery compartment and the magnet is connected incorrectly or the coil isn’t working.

Solution: replace the MG3.

That’s all for today—see you in the next episode. For advice and more, write in the comments or message me privately :)

Brian from BRIANCAMERAWORKS

reddit.com
u/briancameraworks — 7 days ago
▲ 21 r/filmcamerarepair+3 crossposts

Rolleiflex auto fire

Wondering if any of you guys encountered this. The winding lever will auto fire the shutter if it is above 8 feet. Anything at 8 feet and before, no problems. Apparently there isn’t space for the lever to make a full turn or something when it is at further focus.

u/plasticblackspecs — 10 days ago
▲ 3 r/filmcamerarepair

Zorki 6 help

Help. Wind stick stuck up. It moves around but won't go down to lock in film

I bought this Zorki 6 a couple of weeks ago. I tested out the shutter and checked for rangefinder alignment (I had to fix that) but over all the operation of the camera was great. I didn't try to lift this knob because I wasn't trying to load film in it at the time.

I was going to take it out on a photo walk today so I tried to load the film and this happened. I didn't pull very hard and I don't feel like I pulled so hard that anything fell out of place.

Any ideas what could possibly make this get stuck. I looked in the English version of the Maizenberg book on Soviet camera repair and it doesn't say anything about this situation.

u/analog-a-ding-dong — 13 days ago