Sorry to hear that you've joined the club. I'm afraid at the end of many many weeks interacting with Support, the result was disappointing. The three solutions that were provided: factory reset, replace with new HDMI cable and change HDMI port did not work. A regular reboot would last 2-3 days before crackling resumed. If I use the earphones plugged into the remote and mute TV sound, then naturally there's no crackling to hear.
At the end, they said my Roku was an antique (true from 2014, so I did get good mileage out of it) and not repairable, so they offered a 30% discount towards buying a new one on their website. Instead, I recently bought new Ultra LT from Walmart online at lower price, holiday sale $30, but I haven't set it up yet since I use the earphones most of the time in order not to disturb my wife who is doing other stuff.
I speculate that something in the device wears out over time and they don't wish to admit to that to avoid being flooded with replacement requests.
Why don't you put the new one in your living room and move old one to bedroom?