HDMI Hum from Projector -- What To Do?
I just recently upgraded my processor from a Denon 4520 using preouts to a Marantz AV7200mkii. My amp is a 7 channel wyred for sound, so I'm fully balanced there. My projector is a Mitsubishi HC5 and is the same project and wiring as before the processor upgrade.
My noise floor was always dead silent with the Denon, and it is also with the Marantz UNTIL I plus in the project HDMI cable at which point a pretty loud hum comes out of all speakers.
Given that none of the cabling changed, I'm really bummed that I have this new problem with the Marantz.
In order to get rid of the hum, the project has to have the AC disconnected AND the 12v trigger. How in the heck can I fix this???
Steps of troubleshooting I've gone through:
1) removed all other inputs and other hdmi output from preamp except projector, no change in hum
2) Ran hdmi through a splitter/repeater to isolate a ground loop, no change in hum.
3) Unplug projector while leaving hdmi connected to projector and processor. Hum gets quieter, but did not go away.
3b) Unplug projector 12v while leaving projector plugged in, no change in hum
4) Tried HDMI Out 1 and HDMI Out 2 on processor, no change in hum
5) Tried HDMI In 1 and 2 on projector, no change in hum
6) Tried a different hdmi cable, no change in hum.
7) Removed power from projector AND 12v cable, no hum.
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