My box seems to start working ie starts with the purple background animated opening but then the screen goes blank. I have tried disconnecting everything and resetting the box but still nothing. No previous problems with it in the last 8 months and I haven't changed anything like internet connection or anything that may cause problems.
Welcome to the forum. Screen goes completely black? Is the light on the front blinking when you press a button on the remote? And can you hear the confirmation beeps when you press buttons on the remote (assuming you haven't turned them off)?
If you have another TV you can connect the box try connecting it to that and see if the same thing happens - if you get a picture on the second TV try going into Settings and changing the Display Type to 720p and confirming this. Then move back to the first TV and see if this fixes it.