Please provide some information about the hard- and software used.

Dreambox 500s

May be someone can suggest me what to do. It happened in the first day with may DB500s. I tried to change skins and couple times right after changing box halted – screen got black for long time. Only way to restart was unplug it from power. And finally when I wanted change skin for last time my new box died. Even after restarting it shows me black screen. Can I do something to fix this problem or its time to call for warranty repair?