Did he buy a smart phone that was labeled Vertragfreies Handy? That is, one that is contract free. I only know of cell phones being locked-- unable to accomodate another SIM card-- when one has purchased a phone with a network carrier contract. There has to be an instruction's manual with the packaging. There you should find what the default PIN is. As well as the PUK number (when your phone gets locked because you entered the wrong PIN too many times).