"This was a ~3 year old cable that had been working perfectly with 720p signal."
Although 720p native, the AX200 accepts 1080 60/24p (that's what it has always seen through the HDMI port via my belkin cable for the past 2 years without a hiccup).
To rule out any cable fault, I've bought a brand new HDMI cat 2, 10.2gbps certified cable- same results regarding the dots - (mine are also lined up horizontally almost all the time, the other pattern from the pictures I took only appeard once or twice the first time I used the projector).News
: The dots never appear when sending a 720p image (just with 1080/60 or 24p).
You can make them go away by pressing the PC button OR
the Component button before pressing HDMI.
Once they no longer appear, they will not come back unless
you press the VIDEO key
or (probably) if auto detect source is set to ON.
These are 4 of the 5 HDMI cables I've tried (you can see the package of the brand new one). All of these display a 1080p image on a Sharp LCD and my older Panasonic projector without a problem.
tremor13, I was hopping a faulty cable could be the answer, but not in my case. Maybe you don't use the VIDEO input, but if you press that button and then switch to HDMI the dots might come back.. just a thought.