I have a brand new Mag Box 322 bought to replace my 254. Having set it up it loads OK, but when I select a channel the screen goes black and the box turns off. I have a Panasonic Plasma GT30 TV and the 254 worked fine (I just wanted latest technology). I have the video settings set to NTSC 1080P etc. same as before. I've carried out the update too. Any suggestions?