> No sound....
>
> membranes installed correctly, all buttons are working....tried
> triggering from midi....no dice...

If it looks like you can 'auto-tune' and if all the buttons work, then
the machine is at least 90% working (which is a great sign).

> Did the list of calibration routines from the Chroma
> site....nothing....

With the changing of the setup (e.g., RAM/PROMs) you'll need to do a
full setup to get anything to come out - so it is confirmed that you
will have to do the full calibration, esp. the summarized steps outlined
in the "What To Do If You Lose Your Memory" section here:

http://www.rhodeschroma.com/?id=polarisserviceadjustmentscheckout

Part of these adjustments expect/require that you will hear output from
the Chroma. If you can't hear anything as part of those tests, then
that will need to be investigated first (e.g., try both the high/low
outputs, ensure the output lines attached, etc.)

If you can hear output as part of the adjustments, then you should be
able to hear output from the patches - as long as you either have a
scratch patch set up () or have paches otherwise created/loaded.