Tracking down Random Blank Screen HDMI issues

[ginjaninja]

Win 11/AM5/4090
Yamaha RX-A6A/Epsom LS-12000b, 10M powered HDMI cable.
3480x2096 x 120Hz by 10Bit HDR

Every now and then i get a blank screen or Obvious RGB discoloration when I switch on equipment.
So i assume its a 'negotiation' issue.
Occasionally the screen goes blank and comes back during usage..

I was guessing a HDMI cabling/length issue but power cycling AV amp reliably sorts out the problem for another couple of weeks.
I dont have enough spare equipment for A/B testing.
any experience on what these symptoms do or dont point to?

 

[ginjaninja]

Does sound like an issue with the initial handshake.

You said the resolution is 3840x2096, is that a typo? If you run it at 3840x2160 does the issue go away?

ah yes it was a typo...its 2160