You need a multimeter to check the supply voltages, don't touch the trimmers as your voltages can go out of spec and damage the guts. But do get them verified before anything else.
Basic reseating of connectors can help many synths that have been unused or stored in dampness etc. for some time... of course when the synth is unplugged and given time to power down etc.
Did you mention whether you made it over to the main host site for the Chroma Polaris, which has tons of technical details and insights for you to review? It'll give you a much better starting point for follow-up questions etc.
How about the lengthy series of videos by Syntegrator?