my starview box lost signal?

hiya i hope somebody can help me with my problem my starview box is not working anymore ive recently moved into a new house and the landlord had a virgin media contract but had it cancelled when he moved out about 3 months ago and my box was working fine until about 3 weeks ago and now it says no signal, i know its not a problem with the box as i tested it at my sisters house and it worked fine! does anybody have any ideas as what is the problem if so could you let me know! thanks very much