Laptop won't detect HDMI TV anymore?

The laptop is a Lenovo b50-r30 running Windows 10 with Intel graphics.

I had the laptop plugged into the TV yesterday via HDMI and it worked fine. Today I turned both laptop and TV on and saw no picture on the TV.

With the TV still plugged into the laptop I went to display settings and clicked on "detect" and it said "display not detected".

How can I get the laptop to display on the TV?

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