DeckLink 4K Extreme 12G hdmi 2.0 board not working

It should be backwards compatible with 1.4 signals right?
For me I never get any audioor picture if I use the 2.0 daughter board. But with the 1.4 it works just fine.
VIDEO INPUT in the Desktop Video Setup program never shows anything on the HDMI input when having the 2.0 daughter board. But with the 1.4 it correctly displays 1080p60

Yes, it works fine on mine. If you're sure you're connecting everything correctly, it sounds like the daughter board could be broken.

Hopefully Black Magic Design team allow me To send it in for inspection despite having bought it from a guy on eBay. I seem To be the third owner. Do you think I should send them the whole bundle or just the 2.0 daughter board?

ok, so now I ordered a new hdmi 2.0 board and it still will not accept any hdmi signal. What do I do?

What sources have you tried? I assume you set the input to HDMI in Desktop Video?

I have tried:
PS4 Pro (1080p and 4K)
Analogue NT Mini (1080p) <- this works with 1.4 daughter board
Nintendo Switch (1080p) <- this works with 1.4 daughter board

I have tried WITH and WITHOUT splitter and switch. 1.4 daughter board accepts signal with splitter and switch.

I also have OSSC and a PS3 but I haven't tried either of those. I'm pretty sure the Ps3 works with the 1.4 daughter board.

The OSSC I'm pretty sure doesn't work at all with DeckLink 4K Extreme 12G.
However OSSC works perfect with DataPath RGB card and accepts ANY resolution. How come the Black Magic Design DeckLink is so super strict in it's hdmi input signal?

I have tried brand new 2.0 daughter board and the 2.0 daughter board which came installed from the buyer. According to buyer he only used the SDI. SDI I can't use at all since my goal is to use it with video game systems.

I would probably contact support, it sounds like you know enough that this should work without issues. I don't remember having any issues with HDMI input on my 12G card, except when dealing with 2160p60.

Finally was allowed to send the card to the support and they said:
"The HDMI part of your DeckLink Extreme 12G doesn't work properly.
Unfortunately we do not have any more information about the reason.
Because of the compact design of the card we are unable to give you more details
and like mentioned before we can not perform any repair on this unit.

I'm sorry to say that there's nothing more that we can do now.
Because of this we suggest to send your card and HDMI brackets back to your location."

They will not repair or replace anything as the guarantee expired on this specific card a long time ago.

So now 3 months have passed since I bought it from the guy on ebay. Hopefully he can be kind enough to let me return. First i'll have to wait for Black Magic Design to return it to me.

He did state in his original listing "fully functioning" which now 3 months later we can say is not true.

You can buy a new HDMI 2.0 daughterboard and replace it yourself quite easily if the card works fine otherwise. Search for BDLKHDEXTR4KHDMI2 and you will find it.

ok, so now I ordered a new hdmi 2.0 board and it still will not accept any hdmi signal. What do I do?

He already did.

And this is exactly the reason that i'm very cautions with buying BMD gear 2nd hand. Or even out of waranty. If there is something wrong with it. You have a nice expensive paperweight.
As repair out of waranty is almost non excisting so that should be a big warning. And if you already are the 3rd or 4th owner that should be a really big RED flag. Suchs cards are not removed because there is something better on the market. As it is already the highest card you can get...