Xbox One will only output to TV with 640 x 480 resolution

I am having difficulties getting my Xbox One to connect to my HD television. When I power it on normally, the system turns on as it should, but the TV remains saying "No Signal Detected". I followed advice on some other forum posts then and tried to reboot
it by pressing the power and eject button at the same time, this does work and will boot the system up at 640 x 480 resolution. When I try to change the resolution settings back to 720p or 1080p, however, the screen goes blank again and the tv continues to
say No Signal Detected. I have had this Xbox for about a year and have played it on this television at the 1080p resolution with no problems up until this issue started very recently. Any advice or suggestions of what to try?

NOTE: I have also tried adjusting power and startup settings to "energy-saver", and I have also adjusted the "TV connection" setting to HDMI and auto-detect and neither seem to be working.

Thanks

:)

 

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I have the same problem. Following the steps mentioned in help section didnt change anything. Mine is a brand new xbox one S. After a couple of days its just stuck at 640x480.