Dolby CP-950 HDMI Problem

[Dennis Benjamin]

A theatre that I help at had some "used" CP-950s installed recently in several of their auditoriums. In one of the auditoriums, the in and out HDMI ports work and allow a Blu-Ray player to be hooked up and pass the audio and video through the 950 with no issues. In two other auditoriums however, it doesn't work. Additionally, I took the actual Blu-ray device and cables from the working auditorium and set them up in the non-working auditorium and no bueno. That tells me that it isn't the Blu-ray device or the cables. So what in the CP-950 would be the problem? The software version and macros are the same on all units.

Could it be that HDMI ports are dead? (I ordered a tester to test the HMDI ports).

[Steve Guttag]

It could be an HDCP type issue. the CP950 allows one to set the HDMI ports to HDMI 1.4 or 2.0. If working with an older projector (with DVI ports), the HDMI 1.4 would be a more consistent standard (with corresponding HDCP).

Have you tried say your laptop? If it isn't an Apple device, the laptop shouldn't be HDCP enabled for most things.

Here is what the HDMI config screen looks like from within the CP950:

Screen Shot 2024-05-07 at 8.10.28 PM.png

Note, you can also set your up-mix preferences (e.g. pro-logic for 2-channel sources. Now, if only they would offer the same courtesy for the DCP sources!

[Marco Giustini]

Welcome to the HDMI world
As Steve suggests, try something else (bear in mind laptops can be fussier!) and also different cables. I know you said you tried working cabled but I've encountered so many flaky HDMI cables over the years you wouldn't imagine. Make sure they're very short for a test - HDMI was never designed for long cables.

Also make sure you the BD is powered off when you plug the HDMI cable so it can do a proper handshake when it wakes up. Yes, I'm aware that "it normally works when hot-swapped" but HDMI is like that, it's never been designed to be moved around