Cleaning Canon G9 Sensor

After a recent trip to California, I found every photo that I’d taken with my Canon G9 had three distinct smudges on them. Cleaning the lens did not help. The local camera store confirmed the sensor had dust on it, which is a “major repair.” They wanted to send the camera to Canon, requiring at least a month to repair and cost in excess of $150US. No thanks. I’ve cleaned my DSLR’s… how hard could it be to clean the G9?

The cleaning process took about an hour. Have a clean area, a good set of screwdrivers (000 Phillips, 00 Phillips, and a small standard), and cleaning products. For the actual cleaning I used the same solution and sensor swabs that I use with my DSLR. Everything in the camera is tiny so get into your best Zen state before proceeding.

Remove the screws holding the back of the case. Don’t miss the one under the USB port cover.

Remove the screws holding the keyboard controls. Insert a pin through the holes in the cable to the keyboard. You will need to bend the ends of the cable up to do this. The pin will act as a spanner tool and more uniformly transfer force to the cable thereby protecting it. Proceed to remove the cable by gently working with the pin to pull the cable free.

Once the keyboard is free, remove the diopter assembly and unscrew the LCD panel.

After the LCD panel is lifted up, the sensor cover is visible. There are three screws holding the cover as well as some sort of “glue” under the cover near the screws. After removing the screws, you will need to gently pry the cover up with the standard screwdriver. Use your best judgment here. The sensor is exposed under the cover so be careful.

Pry the sensor cover up to expose the sensor. Use your cleaning materials to clean the sensor. I used a sensor swab and followed the directions on the sensor swab. Mainly, make a single authoritative pass with each side of the swab. Reusing the swab could redeposit dust or scratch the sensor. In my case, there was also dust on the filter in front of the sensor. The filter is a tiny piece of glass surrounded with a gasket. Remove the gasket and swab each side of the filter. Do not touch the sensor or the filter with your fingers. Doing so would leave oil and create an even larger cleaning challenge.

Reverse the steps to reassemble the camera. Before final assembly you may want to turn it on and verify that the camera is working and that the image is clean. After the first experience of cleaning the camera you will be a lot more comfortable. Hopefully, the camera will never need to be cleaned again. Good luck.


For additional amazing photographs of the internals of a Canon G7, please see these images as Fotokala.

This Post Has 15 Comments

  1. adx

    Excellent! Huge thanks for posting this. I just did my G7, and can confirm that the process is essentially identical. It also took me an hour including finding the tools (1 hr 3 mins with about 5 or 10 mins of that cleaning the LCD which I managed to accidentally touch…). Almost perfect results afterwards, the camera was becoming useless due to some really big pieces of dust.

    I elected not to remove the IR filter (which was what had all the dust on it, sensor was spotless), because it felt like it was going to break if levered out. So I just directed air duster at the edges of the gasket which are loose and it got in there, also cleaning a lot of dust off the back of the lens. I removed the 3 little springs that push against the sensor plate beforehand. I wouldn't usually spray compressed air into a camera, but when it's already at the 'sharp end' it's only going to blow the dust away. And there was a lot in there. There was one tiny spot left on the far side of the IR filter but I decided to leave it, to avoid the usual "I always go one step too far", in which case I'd still be fixing it.

    Also the keyboard connector is a zero insertion force connector – you can lever the black bar at the back so it flips up, and the flat cable comes straight out. (I only found this out on reassembly, it didn't seem to want to come up during disassembly so I assumed it wasn't ZIF, I managed to tear one of the holes at the end by being lazy (I thought clever at the time) using sharp edged tweezers). Like you say it needs a bit of care, but if you've done this sort of thing before it's on the easy side of "fiddly".

  2. Anonymous

    Just wanted to say a big thank you for posting this. I've had my good old G9 shelved for some time due to dust and other bits that worked their way into the sensor, and this looks to have cured it. (Actually, almost everything was on the filter in front of the sensor.)

  3. Anonymous

    Getting to the sensor is not particularly difficult. Notes:
    The black bar mentioned above (there are a couple) is actually a clamping mechanism on the cable socket.
    Be careful to remove and dispose of the bits of hardened glue on the three sensor screws.
    The 3 sensor springs are really small; beyond my ability….and then I removed the IR filter, the far side of which is where most of the dust and crud resided. Big mistake; very difficult to clean both sides and then get it back into place with the thin rectangular mask and rubber gasket assembly.
    In the end I had a different pattern of gunk, so I shipped the G9 off to Canon Repair. It was worth a try, though.

  4. I tried this cleaning procedure and also had a tough time of it. When I was re-inserting the ribbon cable to its socket a couple of pins popped loose from the socket and now the camera doesn't power on. If you venture to do this repair yourself, make sure you figure out how that cable socket clamp works, and that you have it completely disengaged when you re-insert the cable. There should be only minimal force necessary for re-insertion, and if you exert anything more than that you risk breaking the connector or damaging the cable.

  5. Mary

    "There are three screws holding the cover as well as some sort of "glue" under the cover near the screws." How can I get rid of "glue" safely?

  6. Alfie

    grab a radiator or something else that goes to ground before you do this – static charge can fry delicate components very easily.

  7. Unknown

    Guess I broke the cabel, neither zoom nor full press shutter (only half press, for focus) is not working 🙁

  8. Blair Anderson

    TX to the original poster for this insight to my G9. I likewise have the dust problem that appears to likely be on the filter. I am very dissapointed that my G9 has this dust problem as has been an amazing camera up until two of the small outer body screws worked loose while on a trip to India. All for the sake of some locktite… two lousy loose and now lost screws meant enough movement in the outercase that it has brought me to the end of my Canon loyalty. I feel a Nikon510 coming on…. but I will give this procedure a try. Otherwise I will have the worlds finest skype camera! Though bless em, why they didnt make it so it was powered via USB beggers me….

  9. adx

    Not sure if my ID worked so I'll re-post it:
    ———-
    It's funny some new posts came through just as I needed to do this again (I'm "adx" if it comes through wrong). My camera had grown a lot more dirt – it's fallen onto the floor at least once from earthquakes and I've used it a lot more out and about (these things related). I think I had also upset the focus plane when I cleaned it originally. So I just re-did it. Had I read my old instructions it would have been easier this time, but I wasn't that clever. I chickened out again and decided not to bother removing the IR filter (which is glued at the sides in the G7 – though there are other instructions on the web saying how to cut this out). By "gasket" in my original post, I don't mean the rubber sensor-sealing gasket, but the thin mask which the IR filter sits on. I just blasted air duster past that, in fact while zooming the camera in and out, and it's clean enough now. I suspect removing the IR filter wouldn't do much because it's a very small cavity behind the back element and I think dust will get back in there soon enough, and the more things you remove the longer it takes to get back together which risks more dust falling in there. Another tip is to use pointey-tipped tweezers for doing anything like removing the springs or picking up dropped screws.

    My main point for Mary is to try and retain the glue – this locates the sensor where the factory aligned it. Just crack it open and later screw the plate back down to where it was. Most of my glue had crumbled loose this time so my sensor definitely needed to be adjusted similar to some other instructions on the web (but I made it up as I went along). I was also a bit silly and lost one of the springs while playing with imaging through a Zuiko f/1.4 lens (doesn't work well, with a lot of "digital" readout noise, I eventually realised probably because of no mechanical shutter during readout, the preview and movies were fine). BTW I completely removed the LCD and temporarily plugged the keyboard board back in so the camera would work while open.

    Aligning the sensor was a surprise. I hadn't realised the camera will think it's focussed if it gets to infinity, so if the sensor is set too far away then it will happily take a blurry photo. Flicking into manual focus mode makes it clear what's going on – the camera obviously knows where it thinks infinity is. So I used an object about 2m away and just the preview screen (centre enlarged portion doesn't show up on the external video output) to judge best focus, and make it equal for all 4 corners by adjusting the screws (even pressing on the sensor plate can give you an idea). One of my pieces of glue was still attached so I used that as a substitute for the missing spring, just having that will have helped a lot with my alignment. As it was it took me about an hour, it's quite easy to handle and adjust in this state, but the whole thing could be extremely frustrating if you're in a hurry or expecting it to do what you want. Hmm.

  10. adx

    It's funny some new posts came through just as I needed to do this again (I'm "adx" if it comes through wrong). My camera had grown a lot more dirt – it's fallen onto the floor at least once from earthquakes and I've used it a lot more out and about (these things related). I think I had also upset the focus plane when I cleaned it originally. So I just re-did it. Had I read my old instructions it would have been easier this time, but I wasn't that clever. I chickened out again and decided not to bother removing the IR filter (which is glued at the sides in the G7 – though there are other instructions on the web saying how to cut this out). By "gasket" in my original post, I don't mean the rubber sensor-sealing gasket, but the thin mask which the IR filter sits on. I just blasted air duster past that, in fact while zooming the camera in and out, and it's clean enough now. I suspect removing the IR filter wouldn't do much because it's a very small cavity behind the back element and I think dust will get back in there soon enough, and the more things you remove the longer it takes to get back together which risks more dust falling in there. Another tip is to use pointey-tipped tweezers for doing anything like removing the springs or picking up dropped screws.

    My main point for Mary is to try and retain the glue – this locates the sensor where the factory aligned it. Just crack it open and later screw the plate back down to where it was. Most of my glue had crumbled loose this time so my sensor definitely needed to be adjusted similar to some other instructions on the web (but I made it up as I went along). I was also a bit silly and lost one of the springs while playing with imaging through a Zuiko f/1.4 lens (doesn't work well, with a lot of "digital" readout noise, I eventually realised probably because of no mechanical shutter during readout, the preview and movies were fine). BTW I completely removed the LCD and temporarily plugged the keyboard board back in so the camera would work while open.

    Aligning the sensor was a surprise. I hadn't realised the camera will think it's focussed if it gets to infinity, so if the sensor is set too far away then it will happily take a blurry photo. Flicking into manual focus mode makes it clear what's going on – the camera obviously knows where it thinks infinity is. So I used an object about 2m away and just the preview screen (centre enlarged portion doesn't show up on the external video output) to judge best focus, and make it equal for all 4 corners by adjusting the screws (even pressing on the sensor plate can give you an idea). One of my pieces of glue was still attached so I used that as a substitute for the missing spring, just having that will have helped a lot with my alignment. As it was it took me about an hour, it's quite easy to handle and adjust in this state, but the whole thing could be extremely frustrating if you're in a hurry or expecting it to do what you want. Hmm.

  11. tom waugh

    Wow! I would really feel nervous taking my G9 apart. Kudo's to you sir!

  12. Tony Gomm

    One vital point that you missed in the instructions….First: REMOVE THE BATTERY!

  13. JonBradbury

    Thanks for this, my G9 just picked up a dust bunny bang in the frame centre today, thanks to this stripped, cleaned, and it'll live another day now.

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