Rhodes Chroma Polaris

I'm Edoardo Gennaro.
When i received my polaris, the box was external, thery ugly, so i 
modified it.
Also the Attack slider of filter envelope was not working, I had to re-
solder it onthe board.
Now, the only thing that doesn't works is the E5 key tha plays only 
the maximum thelocity also if you press very soft.
I don't know how resolve the problem.
Anyone had the same problem?
Edo

PS
Polaris has a great sound, is fantastic.
A tweeter killer!