I couple of months ago, I upgraded and replaced my old perfectly working TV with a smart TV: Sony TV KD-55XD8577 bought as brand new. I plugged in Sky HD+ box into HDMI 1, Xbox One into HDMI 2 and external audio system into HDMI 4(ARC). Everything works perfectly well except that the HDMI continues to give me endless headaches. The problem is that I constantly receive the ‘No Signal. Check the external input or select another input using the INPUT buttons’ comment at the bottom right hand corner of the TV. It is annoying because I cannot watch anything using HDMI without first having to physically turn off TV, unplug and reconnect TV from the mains before it starts working again. The TV works fine for Netflix, YouTube or Amazon that do not require HDMI connection. The TV does recognize everything plugged into the HDMI ports but just does not work without disconnecting from the mains before watching something. I have made countless phone calls Sony customer support, I have tried everything but the issue remains unresolved. I have twice done factory resetting after updating and installing the latest software and firmware for the TV. I have tested the cables with the old TV and they worked perfectly fine, leaving me to suspect that the problem could be with Sony Bravia HDMI software. I asked Sony people to tell me if anyone has complained about this issue before but I might as well water a rock and expect it to answer. I have scoured the internet and online forums hoping to find something but still no luck. If anyone has any idea about how I can solve this problem (or are experiencing the same issue) please do let me know via the comments below, thanks.