Core UAC-50

[Swiss]

Today, i got my new core charger. Plugged in the balance board, (the one you get with it), plugged in my sensor lead, (2S). Went through the settings. Set it in lipo balance mode, and after 10-15sec of charging it comes up with an error, (cell voltage). Changed the balance lead changed cells but everytime it comes up with the same error. Plugged the balance lead back into my UAC40 and no problems charging.
In the period of time it is charging if you look at the screen which shows the individual cell voltages, it seems to be showing voltages on 5 of the 6 cells. Which it should only be showing voltages on 2, as it is in 2S mode...
The only thing I can deduce is that the board is faulty??

Any ideas?

P