I've replaced p/u selector switches. I literally spin that after every song so it's not surprising that it would wear out after years.
I've also replaced several of my Schaller tuning pegs. Same story, I change strings a lot and they get a good workout.
And one pickup stopped transmitting a few years ago which I imagine is a rare problem.
Alembic gear is built as robustly as can be. Made to be rolled on and off the truck and work reliably every night. That said, when I have my trunk on the road I carry spare everything, starting with a 2nd complete bass. Plus a small case with cables, connectors, switches, preamp board, and even a spare set of pickups and wiring harness.
Even though the active circuitry of these instruments could be considered complicated compared to a passive axe, I've only had one preamp card fail in almost 40 years (Jeez!) of use. Glad I had the spare card that moment! I can tell the boring story if you want...
Curious to hear from Mica about what the most common repair is.
The move + groove = remove formula is great, and right on the money!
Jimmy J