I've just registered to report my results here as this community post has been MOST helpful to me.
Background: For the past 3 months or more my camera has had a non-responsive shutter like many posters here. Mine seemed to work better after the camera (warmed up) for 20 minutes or so. I could quickly facilitate this by putting it on a heater and it would work GREAT. Pressing the shutter in different ways, with the normal, light pressure but with my finger nail would also seem to get it to function. ALL of this is irrelavent, in my opinion, because it makes this GREAT camera so useless and frustrating.
Based on the reports here, I ordered TWO of the CM1-7226-000 assemblies referenced in an earlier reply, through the official CANON channel. I did this to service it if needed in the future, or in case i did some damage during the first repair.
I used the S100 lens error video on y0utub3 to assist with disassembly order. Keep yoru area clean and organized, video yourself if you can. I did not. I am NOT the most handy person, but I have been building and servicing computers for 20 years as a hobby and job at various times.
My fix worked first try, and I am delighted. Please DON'T be afraid to do this. Total cost for me, even though I ordered two parts (the shipping is the same for one, or two.) including tools was around $50, and for me, these tools are handy to just have around. Prior posts gave me some pointers on tools, as well, so I'll summarize everything I learned here.
You will need:
--PH00 screwdriver (double aught [sounds like "ott"] phillips, will be the terminology if you need to ask someone)
--#1 hobby knife (I have a young son, and found a RETRACTABLE one to add to my toolkit!)
--CM1-7226-000 part
--straight precision/surgical pick
These parts are used for:
--PH00 - goes without saying, this is a screwdriver, use a video to assist with your teardown and keep everythying clean and organized
--#1 hobby knife - used to pry boards away from the camera where there is sticky tape holding things down (be VERY careful not to slip, I'm impatient and DID NOT slip, but be careful, the opportunity to do damage to the camera or yourself is there)
--CM1-7226-000 - this is the part you will be putting in once you remove the bad one
-- straight pick - I used this to put the boards back on their guide pins. The construction on this is marvelous though tiny and precise. I also used it to insert the main plug of the replacement part into it's socket on the front of the camera while holding the board out slightly (there's a hole there to facilitate this. Same thing goes for working with the pick, these boards are thin, never point the pick at the boards, only use it to lift underneath, grab the tiny holes, press down lightly with the EDGE etc. When inserting the big plug, which is the FIRST thing I did after getting the old one out, line up to the plug, it won't go in very far with hand power, just snug enough to bend the tape out from the front toward you, insert your pick, push down gently on the pick while rocking the board in it's slot back and forth gently.
It took me 1.5 hours with these tools, being hesitant, impatient, and never doing it before, i'm VERY confident I could get this time down to 30-45 minutes a second time based on what I've learned.
