UK46MKII no signal !

Hie,
I have some issues with my mixvibes Cross since I've buy it it doesn't work very well:
I've well plug my turntable and sometimes it works I've the signal sometimes i've to close Cross and re-open it to get the signal !
The worst is that: Cross suggest me the uk46 but it doesn't receive the signal !
I've check my vynil, my cartridges , my rca I don't understand .
Is there any solution it's driving me crazy i can't mix actually ?
P.S. sorry for my bad english I'm French.
I have some issues with my mixvibes Cross since I've buy it it doesn't work very well:
I've well plug my turntable and sometimes it works I've the signal sometimes i've to close Cross and re-open it to get the signal !
The worst is that: Cross suggest me the uk46 but it doesn't receive the signal !
I've check my vynil, my cartridges , my rca I don't understand .
Is there any solution it's driving me crazy i can't mix actually ?
P.S. sorry for my bad english I'm French.