Rhodes Chroma Polaris

> after about 1 hours play, my chroma polaris II has
> totally frozen up .  all of its lights are on apart
> from the "assignable control" section, where only
> its volume button light is on ...

It's a shot in the dark; however, for generally bad behaviour wherein 
the LEDs stick on (or off) in funny patterns (and there doesn't seem to 
be a 1:1 correspondence to what you're doing with the keyboard), check 
out the "DC OK Threshhold" section of the "Adjustments and Checkout" 
section of the Polaris Service Manual available on the page here:

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