I recently purchased a U9 and hooked it up to my system but picture cuts out! After a frustrating fault finding session I discovered that the U9 would work plugged directly into my TV through a short HDMI cable but not through my amp (using a known working set of cables and settings - actually I just unplugged my HDMI PVR and plugged this cable into the U9 and no picture!!!) So I purchased a set of 'certified' HDMI cables (Lindy Chroma brand - we also use this brand extensively at work for reliable USB connections) Problem fixed. The non working HDMI cables where no brand Chinese type that whilst they worked fine for my PVR, did not work well with the U9. That a PVR works and a U9 doesnt in exactly the same setup would suggest that the U9 HDMI driver is maybe borderline unable to drive the cable correctly or that a 4k HDMI is much more picky about driving a signal down a cable. The U9 was set to 1080.