They they staying calibrated?
There is not much to a studio color 250.
I would guess the bearing have started to seize up on the main shafts. Take a look at them, and clean them with steel wool.
If that doesn't solve it you could try a tiny bit of Krytox. (The only lube recommended by HES)
If they are losing calibration, I would say likely a motor problem.
Good luck!
