Naim NDS front panel USB/Ipod socket faulty?

My NDS have just returned from service. Front display and streaming card were repaired/changed and firmware update to 4.8 was also performed.
I put back streamer in the system. I have never experienced like this before but
since the repair front panel USB/Ipod socket does not recognize any USB sticks
regardless of brand and capacity. I have tried quite a few of them. Sticks were formatted as
FAT32. I always get this message: ‘NO DEVICE - connect USB/Ipod’

Any idea ?
What should be done ?

Best regards

I wonder if the cable that runs from the streamer board to the little PCB connected to the USB socket on the front panel has become detached (there are plugs at both ends) or was not reattached correctly during the service.

Best contact your dealer who arranged the service to get it checked.