HDMI Issues with Sharp LC70UC30U 4K UHD LED LCD

Two weeks ago (February 1st 2016) we purchased a Sharp LC70UC30U 4K TV from Costco. The TV was a display model which had been in use by the store since November of 2015. In the last two weeks we have experienced a re-occurring issue with the HDMI connectivity. While watching TV, the screen will randomly go blank sometimes for about 2 seconds other times for up to 6 seconds. An HDMI icon will appear in the upper right corner of the screen which shows an image of an HDMI port and directly below the image reads, “Audio” then “Video” underneath that. To the right of the image it reads, “HDMI1” and then “HDMI 1” again in larger font directly underneath.

It does not seem to matter what the source of content we are viewing is, in that the issue happens with Netflix streaming, Direct TV signal and with our DVD player. At first we thought the issue might be a faulty HDMI port. However, after plugging our HDMI cords into various other ports the issues continued regardless of the HDMI port. Initially I had run the HDMI cables into our surround sound receiver and then to the TV. I thought the issue might be caused by a handshake issue between the receiver and the TV and therefore have since connected all HDMI cables directly to the given source; this did not correct the issue.

We have contacted both Costco Concierge Services (the retailer we purchased the TV from) as well as Sharp Customer Service. Costco’s tech had us unplug the TV and hold down the power button for 30 seconds and then plug the TV back in. Sharp’s tech had us unplug the TV, press and hold the enter button and the volume – button at the same time and plug the TV back in. The tech said that this should have caused an “S” to appear on the screen however the “S” never appeared. The tech also had me check the current version which was 14000 (this was the up to date version).

Any thoughts as to what might be causing the issue or how it can be fixed?