lock key?

I have a DURABRAND CG5660-M Digital Set Top Box. When all the connections are in place and I switch it on the red power light comes on at the front of the box then after a few seconds it goes out and a green light appears under the Lock heading. This then prompts me with a message saying, "Enter Lock Key". i think the code is 0000 however when entered the "enter lock key" screen goes away and all goes black, and no buttons on the remote work.