Box Not Working

I'm having a similar problem. We had a box go out in Aug and exchanged ot for another. Came home & set up using all of the same cables, but only get an error page  (video signal has been interrupted. error code 225)

Ive' tried several times to figure out the trouble; even took the box from another room in to check and the low quality box (without the dvr) works fine in there.

We need the upgraded box because it's for the guest room and the holidays are coming now, so I have to fix this! Please help if you can! Thx