Roadstar CD 650USB3

I am on my second example of this player and am still unable to get the thing to work at all. My vehicle is wired to the ISO standard and happily accommodated my old Goodmans CD player but both samples of the Roadstar have been totally dead when connected, no flashing led with the front panel removed and no response with the front panel on.

Roadstar only have a help system if you purchase from them direct which is non-existent customer support if you buy their products from anyone else... a poor state of affairs and not at all conducive to buying any more of their products.