Receiver HDMI problem


Have a Marantz 7008 for which I already had HDMI board serviced. Running 35' HDMI cable to projector. Connected to Marantz is cable box and Apple TV.
Situation: HDMI cable from Apple TV directly to projector no problem everything works normally.
2) HDMI directly from cable box to projector = no signal
3) Connect 35' HDMI cable from projector to receiver = no signal from cable box or Apple TV Called Marantz told me to use booster so bought a Gefen Superbooster plus. Still no signal.
Everything points to long run cable problem except how come connecting long run from Apple TV to projector works but not directly from cable box (2). ???
What's going on and how do I fix this?
Thank you. Tom
tkolb
Thank you to everyone. So I'm going to start working through these issues. I have blue rigger HDMI cables for the long runs. I first started with CAT 5/6 to HDMI converter from monoprice but the converter blew within a week. I though it safest to accomplish my hookup by using 35' HDMI cable which I snaked through the wall. Actually I snaked 3 cables for redundancy.
What about using an HDMI BaseT over CAT instead of HDMI?
To answer a question I do get normal 9.2 Audio from my cable box through a marantz 7008 receiver but no picture.
I will also likely try the EDID solution someone mentioned as it's simple enough to try (and return if unsuccessful)
Tom
The Monoprice HDMI extenders do not all work and are finicky. Never use passive extenders and there is only one monoprice extender I've found that works.

I'm using an active monoprice HDMI extender to take care of a nearly 90 foot run. I'm only passing 1080p and I'm using dual Cat5e cables. It's for a 2nd TV and not that important for me but it's been solid. I would suggest running the THX-certified able to future-proof you for 18gbps. Note that you must home-run the cables to each transceiver. You cannot go through a patch panel. Both wire runs also need to be the exact same length or you'll have issues.
Do you mean an HDBaseT extender? You would favor that over 35' HDMI run? Do you think that would solve no signal issue through receiver or still EDID or some other issue?
So, you've never gotten video from the cable box over HDMI. What model/brand of cable box? Is there a setting in the cable box to address HDMI output?
PrPixel is correct. Depending on the cable box, HDMI video and HDMI audio are independent elements. Personally speaking, I would strongly advocate for a certified cable home-run. The HDBaseT extenders, are ok but an evil to use when you can't do a home run.