Hello and welcome to JustAnswer! I am Pete, a TV expert, and I'm happy to assist with your question today.
hi, can you help me?
Yes, I will try my best!
This problem can occur if your TV does not support the resolution selected in the Xbox menu.
You will need to use another TV to change the settings again.
Try setting your Xbox resolution to 480/576p.
if i change the resolution on another television will it save for this one?
The settings are saved inside the Xbox.
But it worked before? Same Xbox, same tv.
Someone may have changed the resolution settings in the Picture Settings menu.
Definitely not, no one is ever near my Xbox
Then it may have been changed by an update or something else.
Either way, you will need to check the resolution setting.
Doing it now, though my tv supports 1080p
While you are checking the resolution, can you also check that the HDMI Color Space is set to RGB.
Once you get the Xbox working on your Vizio again, you can go back into the Picture Settings and set the resolution to Optimal. The Xbox will then select the best resolution for use with your Vizio TV.
It is set to RGB, tried 720p and 480p. Nothing.
Just says "Not Support"
You have tried changing the setting on another TV and moved it back to your Vizio?
What is the exact message you are getting?
I already Googled this issue.
What are you trying to do to solve the issue?
I did this because I thought you may know something different than what is suggested on Google, I can do that myself. Thanks though.
If changing the resolution and HDMI Color Space settings does not fix the problem, then the fault lies with either your HDMI cable or the TV itself.