The screen keeps flashing and there’s no volume

[Mary76Boy]

when I first turned on the tv, it said on the screen,  "HDCM Cannot be supported ".    Something like that. 
I finally got in but now the screen keeps flashing on and off and there's no volume

[Greenfingers001]

Hi there @Mary76Boy , I’ve escalated your post to our Community Messaging team who will invite you to a private chat shortly and help you with this. 

Just look out for the colourful bubble to start the conversation.

Here's more information on how Community Messaging works - https://helpforum.sky.com/t5/Did-you-know/Escalating-a-post-to-a-Sky-expert/ba-p/3711147