Switch turns off every few hours

I bought D-link switch d-link_dgs-1008d ( http://mojmikro.si/pod_lupo/strojna_oprema/d-link_dgs-1008d ). It was working fopr tweo week and after that problems. The router is connected to the electricity but all light are turn off. After I unplugged and plugged it in electricity it worked. After 15 hours same thing happend again. It has green technology. Are this problems related with green it ?

thank