Studio Spot Error Code

Hi there,
one of my studio spot 575's is showing an error code which isn't shown in the manual, namely:
CLR1 or possibly CLRI

It flashes HOME - CLR1 - Err
then points towards the ballast after striking up.
Obviously this is a colour error, however colour wheel 1 tests fine, whereas colour wheel 2 appears stuck between two frames.
Any advice or suggestions?
Related