Man vs. Computer
So I had this little coin cell wired cycle computer, that's always been a bit flaky. Last summer I broke the cable and so the weekend before my first Century I took apart the base and re-wired it, and it seemed to work.
Unfortunately, the next morning when I twisted it into the holder in the 5am dark, the screen cut out. Tried it a few more times, then undid the ties and electric tape, stuffed it in my bag and rode un-instrumented.
Just found all the pieces again tonight, and tried to fix it. Same behavior - works fine, twist it in the base and the screen cuts out.
This was really puzzling. I tried putting tape over the electrical contacts, so it shouldn't even "know" if it's in the base - but same issue.
Squeezing it in various ways couldn't cause the problem.
Re-bent the battery contacts, taped some cereal box cardboard on the foam battery pusher in the coin-screw cover, nope, still has the problem.
Noticed the watch crystal inside might be touching the battery contact, so carefully pushed it out of the way, but no dice.
Finally gave the little spring-contact pins on the back that connect to the base a good solid push individually, and... gotcha! the screen cut out.
Looking through the battery opening, the little springs that push out the nubs sit on the circuit board, and one looked to be just sometimes touching the flat ring that is the base of the battery contact.
Couldn't get anything under the spring through the battery door, so got a knife and cracked the plastic at the mold line all the way around. Put a couple layers of tape between the battery contact and the spring. Re-positioned the spring. Taped the watch crystal, too.
Then I had to spend a good 10-15 minutes trying to find the superglue, that I had just seen last week.
Victory is Mine!
(in all seriousness, I'm sure it will find another way to break tomorrow)