I'm having the same problem. 4770K having issue with HDCP in my HTPC build. I've tried both 1.4 hdmi cables and dvi to hdmi cables. Nothing works. Black screen with audio on copy protected channels.
I'm running HDMI to my receiver and then HDMI from my receiver to my TV supposedly everything is HDCP compliant. If I pop in a gtx 650 I have no issues. Everything points to a lack of HDCP compatibility with Intel's graphics solution.
I would like this to work since Intel advertises HDCP compliance with their onboard graphics solutions and I'ld rather not needlessly run a graphics card in my HTPC just to suck power and as a work around to a lack of feature support on my cpu.
From what I have found on the web this has been a known issue for over 6 years.