My old Canon PowerShot SD1100 IS sat for years and I had thought might be a candidate for exploring CHDK. But something went wrong when I turned it on. Now it makes atypical noises and shows "Lens error, restart camera" after failing its startup sequence.

The bad news here is that camera internals are intricate, so I don't have great expectations for a successful repair, but I have little to lose by trying. Besides, if there is a mechanical issue, I want to see if I can find the point of failure. The good news is that Canon engineers designed the camera with repair and servicing in mind. There were a few pieces of small double-sided tape here and there, but for the most part the camera is held together by fasteners. Making it far easier to disassemble non-destructively than most modern consumer electronics.

There were six externally-accessible small Philips-head fasteners. Two left, two right, and two on the bottom. Once undone, the front metal face plate can be removed to expose the main logic board and all the yellow FPC (flexible printed circuit) plugged into it.

Four of those six screws also held the rear face plate, which mostly covered the LCD screen. One interesting side note about the screen: it has a wide FPC which wound around the bottom to be plugged into the main logic board consistent with a high-bandwidth connection for low-latency video viewfinder. But there is also a tiny FPC up top with just two visible wires. It plugged into a connector directly behind the camera flash. This is likely for screen backlight. This camera might be old enough for a fluorescent backlight, in which case it made sense to consolidate all voltage boost converters into the same area within the camera.

A few more fasteners became accessible once the front and rear were removed, most of which released black exterior pieces cover top, bottom, and sides of the camera. Then I got stuck. I removed all the screws I could find, but nothing else seemed to come loose.

The key breakthrough was realizing the rear display LCD was held by more than just screws. There were also two metal brackets that were clipped into place by their clever shapes. Once I figured out the physical puzzle of their retention mechanisms, the brackets were freed and I could remove the screen.

Behind the screen is a large number of fasteners in multiple layers. The outermost ring are holding this rear chassis metal plate to other chassis components. Inside that set are screws mounting the black plastic lens assembly to the metal plate. Then screws that hold pieces of the lens assembly together, and the innermost trio held a metal plate that I expect to be part of the main sensor assembly. I'll work my way from the outside in until I can free the lens assembly.