I have an xbox and I plugged the hdmi up to my projector and it has signal but no picture sometimes I can switch from av1 to hdmi 1 quickly and the picture will be there for one second
The Xbox may be sending a higher definition signal than your projector can handle. Check the specs of the projector and set the Xbox to output the "native resolution" of the projector not the highest resolution it says it can handle.
I did that and it still flickers on and off I also hooked it up to a DVD player and it still flickered the red whit yellow cables work fine but I need hdmi