PFC Yoke Aileron problem

Hi,

I recently bought a second hand PFC 737 USB Column Yoke.

However, the aileron axis has always been giving me problems.

I checked the raw x axis data in Windows and it flickers and does not settle on one reading when the yoke is idle.The y axis data is fine and shows no indication of a problem. Has anyone else experienced a similar problem? My feeling is it is a dodgy pot...
Having spent a fair amount of money I just want to get it working so I can enjoy flying. As always all advice and guidance appreciated.

Thanks

kalz