Not many Jaguar CD units were made, and those that did tend to have at least one of a few common problems after 25+ years of use, sitting in storage units, etc. Linkovitch has written various useful repair guides to help people with modest soldering/DIY skills repair some of these issues. His guides are linked below. I've expanded on these with some additional pictures and guides to repairing additional issues I've run into. Hopefully these guides help keep more of the few CD units that exist in operation and out of dumpsters.
Thanks to Linkovitch for the guides, and everyone else who has posted helpful information about issues with the Jaguar CD on the AtariAge forums over the years.