Solved! TV stopped working as second display for my PC after game crash

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I have been using my TV as a second display for months now, mostly when playing video games, and yesterday, when Fallout 4 crashed, the picture crashed with it!

Now, the PC seems to still recognize the TV, as in, I can find it in my display settings and I can change the display settings for it, but there's no picture to the TV.

My monitor is fine, but if the TV and receiver are on when I boot up the PC, the PC treats the phantom TV as the primary display(since that was the setting when it stopped working), and opens every new window on the TV(that I cannot see). So I have to turn the TV off and restart the PC.

Other things like PS4 and Wii U still work fine on the other inputs, and I've switched the HDMI from the PC to another input on the receiver, and that doesn't work.

I am going through a Yamaha receiver, but the PC never recognized that before, and just appeared as though it was connected directly to the TV, so I'm assuming the receiver is not a part of this equation.

And since other devices work on the TV, and this began right when Fallout 4 crashed, I think I can safely assume the problem is not with the TV either.

The PC and TV are connected through HDMI, my graphics card is a GTX 980, and my TV is an LG 65LF6350.

Edit: I've unplugged the HDMI cable from the receiver and plugged it directly into the TV, and it still did not work. Then, I plugged the same HDMI cable into an old 720p RCA I had in my closet and the second display did work on the older TV! Which really only leaves me with more questions than answers...

I uninstalled all games, reinstalled Windows, and reinstalled the drivers for my graphics card. I'm really at a loss of what to try next.

 

[Subtlety]

EDIT: It was the HDMI cord. I got a new one, and haven't had this problem since. I was wrong in assuming it had something to do with the game.