Symptoms of HDCP not working when fed to a display are:

1. Flashing/interrupted video
2. Constant/interrupted picture 'noise' (like tuning to a non-existent TV

3. Blank picture
4. Problems with the source (might be a HDCP reception problem)

Possible reasons are:

1. Output display does not support HDCP - check the user manual to make sure.
2. Output display does not support the video resolution you're feeding it (change the 'Output res' in 'Adjust outputs').
3. Output display is DVI-only, but the C2 unit is sending out HDMI (change the 'Allow HDMI output' to 'Off' in 'Adjust outputs').
4. DVI / HDMI cable is too long. Most systems are recommended to be 10m maximum. Shorten the cable to see if the problem goes away - or use a lower resolution.
5. DVI / HDMI cable is made of multiple links. Never use cable extenders or joins and remove adaptors wherever possible, as you will get signal problems.
6. DVI / HDMI cable is poor quality. Generally, the thinner the cable the poorer it will be and will have problems on longer cable runs or higher resolutions.