HDMI cables can go bad. I had one instance where the signal from my bluray player randomly goes out. To isolate the problem I changed my HDMI cables and found out that it was indeed a bad HDMI cable (with an unknown brand so I will consider it generic).
I got some spare, moderately pricey HDMI cables of the "Cobra" brand (this is the one that can bend at the angle you like) and my signal problems went away.