Canon S100 Shutter Button Fix

This is my Canon S100 digital camera. After long, somewhat arduous service, the shutter button started playing up: it would focus but not take the photo. Eventually I got a mobile phone with a better camera and quietly forgot about the Canon. The S100 has been extensively frozen, boiled, soaked, rattled and trodden on, so I figured that the shutter button problem was just due to the abuse. It doesn’t owe me anything. However, it’s still useful for some things the phone camera won’t do: it fits a tripod, and has good long exposure and manual control facilities including a handy neutral density filter.


Trying to use it to take some tricky oscilloscope photos the other day, the shutter button got really annoying. I searched on line for the problem and discovered that it’s quite common. That sounded like an interesting problem to me. Here’s my attempt at fixing it.

Before we start, don’t try this unless you’re used to dealing with annoyingly tiny things and have the tools to match: jeweller’s screwdrivers, tweezers, a very fine soldering iron and either amazing close-up vision or a good magnifier.

The camera comes apart surprisingly easily. There are six little black screws on the outside: two on each end and two on the bottom, close to the tripod mount. Take those screws out. The back comes off very easily – take care not to lose any of the buttons though.


The front also comes off easily, though there’s a little FFC connector to the setting ring round the lens. Unplug it carefully. It doesn’t have a locking bar so the flex PCB just pushes in and out. There’s also a foam gasket round the lens and the plastic cover for the HDMI and USB sockets. They’ll fall on the floor.


The shutter button and other controls are underneath the top cover. There are two more screws to remove: one on the front near the lens and one on one end. They’re different lengths so take note of where each came from. Before removing the top, there’s one more FFC to unplug. This one connects to the microphones. Again it has no locking bar so just pull gently. It’s the middle of the three FFCs in this photo.


With the top cover off, the controls themselves are revealed. On the left here, the function selector rotary switch, then the shutter button and zoom switch, then the power button, and on the right the big square thing is the GPS antenna.


If you put the battery back in, the camera actually works fine in this dismantled state, so it’s easy to try experiments. I prodded and poked the shutter button. Sometimes it worked, sometimes it didn’t. I doused the button with my favourite contact cleaner (DeoxIT D5) to no avail. I looked on the web for replacement buttons: “double action tactile switch” seemed to be the best thing to search for. There are lots out there which might fit, but they’d take a while to get hold of and would be really fiddly to solder, especially with the zoom switch so close by.

I wondered about a mechanical solution, extending the plastic rod from the outside shutter button that presses the switch to give it more poke, but sometimes the switch just refused to work no matter how hard I prodded it with a screwdriver, so that probably wasn’t worthwhile.

Given that it wasn’t worth spending a lot of time on what’s effectively a life-expired camera, an alternative engineering solution was called for. The first stage of the shutter button, the half-press to lock the focus and exposure, still works reliably. What if I just wired it in parallel with the shutter release contact? Then there would be no way to lock the exposure and focus, but at least the camera would take photos.

Some fiddly soldering with a fine iron bit and some polyurethane-insulated mod wire later, the two opposite corner contacts on the button are connected…


…and the S100 lives again. It’s not a full fix, call it a workaround, hack or bodge, but it’s good enough for me to take pictures. Oh yes, and assembly, as somebody once said, is the reverse of disassembly.


7 thoughts on “Canon S100 Shutter Button Fix

  1. Po Yeung

    Hi, Martin! Thank you for showing the hack you made on the S100. I Have the same S100 shutter problem. I really want to repair it because I really like this little camera. I shall try anything to make it work again. A while ago, I took a long video (5 minutes) with it and the shutter began to work again for a while and sporadically. I suppose the heat generated helped the shutter contacts to come together. Anyway, I wonder if you can get focus as the two action is done simultaneosly. I know you cannot pre-focus now but does it focus when it takes the picture? I am eager to know because I might try the same thing as you did. Thanks!

    1. martinjonestechnology Post author

      Yes, the camera does focus when the shutter button is pressed. It takes a fraction of a second to set the focus and exposure, then takes the shot. Not so good for action photography, but fine for most uses.

  2. Dan

    congratulations on fine soldering skills. Did you use a sophisticated temp controlled iron, or just a really small pointy one. It looks like there would be a real risk of melting and other collateral damage.

    1. martinjonestechnology Post author

      I would have used my proper surface mount rework equipment if I could, but I did the job at home with an Antex 1.5mm bit, 370 degrees C, 0.4mm Fluitin 1532 SAC305 96.5%Sn 3%Ag solder. A finer bit would have been nice but only on a really good iron – lesser irons have real trouble getting the heat into the joint with a very fine tip. I do a lot of fine soldering in the day job, so this one wasn’t too scary.

  3. Eric

    Hi, Martin! Thank you for showing this hack. Like many S100 users, I have the same problem with the shutter button. I try to test your fix making contact with a very thin wire before soldering. But all my tests were unsuccessfull!

    1. martinjonestechnology Post author

      I’m sorry to hear it didn’t work for you. It’s very fiddly to get the contact in place. Or perhaps your camera has a different fault, possibly a break in the flexible PCB which holds the buttons.

      1. Eric

        Yes, It’s very fiddly… Honestly I tested a lot of combinations to try to get the contact and helped with someone else. Do you have a photo showing the soldering contacts more closely ? And good luck for anybody doing this hack 🙂

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