Verified answer

Make sure that the HDMI cable is inserted to the correct port in the Xbox.

Check both ends are securely fitted inside their respective sockets.

Make sure the sockets are clean

Cycle through the inputs of your TV with the Xbox on, all of them

If none of this works, aquire the other cable that came with the Xbox (or get another one) the Red Yellow White one and try that, see if the Xbox actually works.

Side note make sure two outputs are being used at the same time

If all else fails, contact Microsoft support or your local computer shop

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