Casio CZ/ VZ/ FZ - Pro Series

I left the manuals at home (darn!) so I do apologize
for asking the perennial question: is there a battery
in the CZ-101 other than the C-cells in the main
battery compartment, for backing up the memory?
My synth doesn't make any sound when I choose
"internal" sounds, whereas it sounds fine with
patches from the optional card, and with internal
patches.

Also, what't the best replacement for the internal battery
in VZ-8m? Has anybody tried to mount a battery holder for
a couple of AA cells, instead of the soldered down lithium
battery?

That backup battery design really buffles me. To properly
replace it, one would have to remove the board altogether,
unsolder the battery on the other side of the board, then
solder a new one. That really is a major chore.

I successfully modified myquential MultiTrak with two
AA batteries in a Radio Shack holder, was thinking maybe
should do the same here.

thanks

Maxim