I swapped boxes with the one upstairs works fine now. I did buy a new black box as well but for some reason it wont connect to the internet either wirelessly or wired. The box see's my internet but will not connect to it.
When was you trying to setup your new NowTV black box it wasn't between 13.00 to 21.00 hrs today by any chance?
Also, was there any message coming up on your TV screen and what is the make & model of your Router ?
It's strange that one of your nowtv boxes works on your home network, whilst the newer nowtv black box doesn't want to connect to the internet either by WiFi or Ethernet.
I am guessing you have tried a full factory reset on the black box by pressing a pin into the reset hole for about 30 secs until the initial setup page reappears back on your screen ?
Another long shot try leaving your Router switched off for about 15 mins and i know this doesn't make sense, but perhaps try a different HDMI port on your TV.
Out of interest can you also confirm back your Router make and model.
Hopefully more helpful forum members will chip in with some useful suggestions to try, before taking the box back for a replacement under warranty.
Make sure that your TV screen Is switched on to the correct HDMI input source when factory reseting the box and hopefully the initial setup page will reappear on your TV screen after pushing and holding a pin in the box reset hole which may take up to 30 seconds.
If you are using a wireless (WiFi) ethernet connection, have you selected your routers 2.4GHz or 5GHz frequency band/channel option?
Your NOW TV box(es) really need to be using your routers 5GHz option. Or better still, use a 'hard-wired' ethernet connection...