U-Mix: Jog wheel no longer does vinyl mode

Hi guys
One of the jog wheels has failed on my U-Mix; it continues to work in the "CD mode", where it can be used for phase adjustment, however it no longer works on the vinyl mode for scratching, no matter how I set the adjustment control.
What do I need to do to resolve it?
One of the jog wheels has failed on my U-Mix; it continues to work in the "CD mode", where it can be used for phase adjustment, however it no longer works on the vinyl mode for scratching, no matter how I set the adjustment control.
What do I need to do to resolve it?