So I have a Canon SD870 IS which broke a few weeks back - the lens was stuck and couldn't close, and as a result zooming and focusing did not work at all. If i tried to push it I would get "Lens error, please restart camera" or something along those lines. As far as I can tell, it was the result of accidentally turning the camera on inside its case, so that the motors tried to force the lens open and failed.
A few days ago, having nothing to do on a summer day, I decided to take it apart and see what I could do. It was destined for the garbage the way it was, so there was nothing to lose. After taking it apart, I realized that I could - and did - fix the camera. The lens now opens and shuts nicely. These are some pictures I took with my sister's camera during disassembly to help me remember where the screws went.
A few notes: 1) I found later that the flash capacitor is sort of dangerous. Thankfully I didn't touch it, but just so you're aware. 2) The camera isn't fully fixed - the focus is still a little blurry, and I think this may be a result of my misaligning the gears inside, and/or smudging some sensors. In other words, if you try anything I take pictures of here, do so at your own risk.
To begin: the 'closed' position of my camera.
As you can see, the lens is non in a particularly good place, and is twisted at an odd angle.
Other side of the camera - this is what is behind the LCD screen (the black thing on the right is where the LCD attaches). The metal is the back plate, the black underneath is the lens assembly that I'm trying to remove, and the center metal plate is the back of the optical sensor (or whatever its called).
From the other side. In blue is the flash capacitor - don't touch that. In red is a section where there are two little tab thingies that you can pull out and reattach later; you can't open up the lens assembly otherwise since the orange ribbon is in the way. In green is a tab that you have to lift to open the thing up - there's gears inside, be careful you don't lose any.
Opened up the whole thing. What I had to fix was the inside few pieces, and you can remove them all. Just a note, the funny thing on the left side of the screen, you have to remove that and its attached ribbon before removing the rest of the lens. Its sort of annoying to thread through the hole in the lens assembly.
Screwed up part number one. It may not be apparent at first glance, but there are three ways to put this together (the little tabs being 120 degrees apart). Only one is correct. You'll know which one when it depresses all the way, hits a little spring, and closes the dust shutter, as shown below. Call the top one A, the bottom (with the lens) B.
Same two pieces together, A inside B.
The assembly in the picture previous (with the dust shutter) sits within this one. The problem was this was misaligned as well. Call this ring C, and the thing with the ribbon and the eye D.
The way this works, if I remember correctly: A snaps into the top of C, which keeps B inside. The little knobs around the rim (3 on A, 3 on B) should correspond to the 6 slots in the rim here of C. The weird thing about D is that it sits inside A. It may take a few tries to get the alignment correct. Again, this part D only sits in C in one particular way out of three - it should be able to rotate and follow the little tracks inscribed within C. One of the pieces has a smooth strip inside corresponding to where the ribbon on D is, make sure that is aligned as well.
When you've got everything aligned properly (you can use your hands to turn little knobs everywhere to test it), and if need be, cleaned properly, go and put everything back together. Make sure the lens is in the closed position when you put it back together with the outside gears, especially with the gearbox pointed out before (I think this is where I misaligned by a tooth or two). Screw everything else back, put the battery back in, and it might work =D
