Currently we have the Samsung un60j620dafxza. While playing ps4 one day the signal dropped and now none of the HDMI ports show a signal. We have utilized multiple brand new cables, ensured the TV and devices were up to date, factory reset the TV, unplugged everything overnight and then started from the beginning. After leaving it unplugged completely overnight it worked the next morning for about 1 hour before cutting out again. The USB ports work and apps all work, just no response from either HDMI port. There is also massive light bleed on darker screens, but that's a whole nother issue.