Thanks to everyone who's offered tips and help as I fix one of our XL1 cams. The other one is working fine, aside from that annoying magenta color shift common to this line.

Normally I use 18% gray cards to white-balance the cameras I use together (Canon for closeup, Panasonic for wides), but I notice the Canon and Panasonic 'balance' differently. Do I need to make a more 'pinkish' white-balance card for the Canon, to trick it closer to the Pan?