Keep getting error code 775, comes and goes incessantly

I keep getting error code 775 - it comes and goes incessantly, some days it is fine and others The TV is almost unwatchable. I have checked every single connection and everything is good and tight, and I have replaced the cables I can gain access to. Sometimes, when the error screen is showing, I will test the connection through the DVR and it tests 100%, even when the error screen is showing - other times the test will show the SWM isn't getting power. I have checked the SWN (which is in our attic) and it is plugged in and powered up, so I have no clue.

Could a power adapter be going bad? Need a new SWM?