TV going bright and dim
I just recently got a denon AVR-x4200w and have noticed that my screen will go bright and dim slowly. It was a refurbished AVR so maybe that's why it was returned to begin with? Or do I have some sort of setting or unforeseen interaction with the components? I haven't been watching TV until recently so I can't say for certain it is the receiver.
TV is a Toshiba 65" 4k black friday special that I got in december 2016. The only source I have on it is an xbox one s. Previous AVR was Denon AVR-1712.
Again I have barely made use of it so I can't say for certain it happens outside of bright scenes in a show, I don't notice it all of the time. I might call Denon support as I need to talk to them about my sister and brother in-laws Denon which trips the auto protect less than 2 year's of ownership.
Oh, one thought.... When I set up a Denon for my legally blind uncle years ago I had a ton of issues and it all came down to the HDMI cables I was using, I'm actually uncertain if both cables in the setup are good for 4k. (If you can't tell I'm a Denon fanboy, my sister, uncle, parent's and me all have Denon)
edit: sorry for doing zero trouble shooting before posting, I'm wore out doing general tech support for friends and family and want an easy win.