We've had our Roku replaced once before, the plug in in the tv is loose on both plugs an if u tap the cord or bump the tv, the tv has the black an white fuzzy then goes purple an I get a hd something screen an tells me to reset. I do but it's still hella sensitive. It just doesn't fit in the port in either of them. It's a Samsung tv.
Oops - just reread your message and I think you're talking about the TV's AC power cord? (Meaning this is not actually about Roku at all?) I guess there too, trying a different cable could help. Usually those are pretty tight. Are you sure it's pressed in all the way?
the cord is in the hdmi 1 or 2. it went in easy but it wiggles back an forth i feel like its ill fitting. we've had a replacement because it buffered too much but even that one wiggled. the screen will say no signal out of no where and the colors the screen turns is mostly purple an green. then the hdmi warning pops up an we jiggle it an the warning goes away. im just not even sure what to do anymore.