Sorted thanks guys at the initial trial I just tried an ipod into channel 9/10 on phono cable and when it did not work just thought that was that, but today I went from my laptop into the usb and it worked fine and then tried ipod to xlr cable into channel 1, 2, 3 ,4 and they all worked fine so now I know if need be I can buy another JBL,
thanks again for you help and patience.
Den