Black screen & messed up resolution

[SuperShires]

Hey guys, my main monitor gets screwed up when I turn my AV receiver on to connect my PC to my tv, like when the receiver is on my monitor loses signal and goes black, but it never did this until yesterday, when I turn my receiver off though it displays again but the resolution is all messed up and the text looks like its bold for some reason.

 

I reinstalled the latest drivers and it fixed it yesterday for the rest of the day but its done it again this morning when I do my usual catch up on youtube...

 

Any ideas on what the problem is and how I can fix it?

 

I run my 1440p monitor using a displayport and a HDMI to my receiver. Thanks

[SuperShires]

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