I actually cracked mine open.. quite the exercise in patience, but didn't see anything on the mainboard that looked of interest. Once opened, I also tested by pressing the contacts directly, just in case the buttons weren't making full contact, with the same result.

The trick, if you want to give it a go, was to work something (I used the lever off a pair of nail clippers, because it's smooth and less likely to scratch the plastic) in under the lip around the sides. Once in, sliding it around the side popped all of the clips, and the face came off. There are a number of wires clipped to the mainboard, and the battery connector soldered on, so separate the two halves carefully.

If you decide to try it and find anything of interest, let me know. Thanks for the updates!