HDMI is notorious about "handshake" issues with TVs/receivers, etc.
For example, when I connect the HDMI from my BD player to my projector, it works perfectly. But when I hook the BD Player HDMI to the OPPO HDMI box first, then to my projector, I get nothing at all.
Another issue I had with the PS3 + HK247 when I owned one was the video setting on the PS3! At first I got nothing at all. Then I had to play with the video setting on the PS3. I can't remember, but I had to change the 60fps to 30fps or vice versa or something like that.
Did you set the HDMI output resolution to AUTO instead of 1080p? If the HK is 720p or 1080i, it might not work unless you change the PS3's setting to Auto or something.