Recently picked up a “non-working” LP, non-USB version. It plays, all the buttons work, etc. However all 4 big knobs don’t work - they jump from full on and off only. I had a tech look at it and he thought maybe the board controller CPU/ROM was bad, reached out to Moog for parts, etc, but never heard back from Moog.
Anyone else had this same problem? Thanks 
Moog have recently changed their contact platform, you need to apply here https://moogmusic-help.freshdesk.com (click on the sublink at the bottom of the page to login as Customer)
Back to your issue, I find it is simplistic jsut to say that “CPU/ROM are bad” since all the rest is working (as you report), only a qualified technician who has the LP schematic and knows which component(s) are involved in the scanning the 4 pots can diagnose the problem properly.
Replacing encoders is a more common fix than a bad CPU/ROM. If you’re not comfy soldering, getting a quote from a synth repair shop might be the way to go. Good luck getting that LP back in top shape!