Xbox getting no signal with HDMI

With the amount of (4K) bandwidth that gets transferred over HDMI, you're definitely pushing the limit at 50 feet. There's no established cable limit for HDMI, but there are reports that the maximum reliable signal goes around your 50 feet (~15m), using
the absolutely best quality cables.

Attenuation (or weakening) of the electrical signal over that length of HDMI cable is causing it to not display anything. As HDMI is a digital signal, you will either get a perfect signal, or nothing at all.

You will have to consider getting an active HDMI repeater to extend the signal between those 50 feet, ensuring it supports driving 4K@60Hz.

It's a tall order to support this kind of 4K setup. Have you considered moving the Xbox closer to the TV? lol.

ive changed hdmi cables and the cable is fine, I get the green xbox screen and then just a black screen at the end of it...no dashboard !!!!..i know its sending a signal because if I unplug hdmi cable the tv states no signal...

I have this exact same issue, but with an Epson projector. The problem can be resolved if you disable the instant on function. I believe the issue is the fact that the xbox sends the first power signal, then cuts the hdmi signal, then sends the second power
signal. When the hdmi signal is cut, it cancels out the first power signal, making me press power on the projector remote once to get it all the way off.

Cheap HDMI or expensive there's no difference they all send the same digital signal you either get a signal or you don't.

It's not a switch. It's a HDMI Repeater which routes the signals via processors and outputs the signals to the HDMI output. There is no direct passthrough, without processing the data first and adding a delay in signal.

You have shown no proof in the HDMI signals being directly passed through without being processed and your assumption on 50-133ms of Xbox 360 processing delay on Campaigns is Ludicrous too...