FW800 to FW400

It's a 2009 4,1 flashed to 5,1.

It has 4/FW800 ports but none of them work.

I tried that, can't see it in system information.

I can see that the Mac drivers are installed.

I agree, it should work seamlessly but it doesn't.

I did manage to get it to work when I downgraded to El Capitan but as soon as I upgraded to High Sierra it stopped working.

I tried a Startech FW400 PCIe card but that doesn't recognize it either. I see the Startech drivers but that's it.

It claims to have the TI-chipset but it's for windows 10 and may work on older macs.

I will test it on my 2,1.

I also have a G5, a 2,1 and a 3,1 and they all work perfect so I can rule out all cables and interfaces.

My intuition tells me that the ports could be shot or the board has some issues.

I hear that Allegro makes a card that should solve the problem, do you know of any?

In the worst case, I will have to replace the FW800 ports or the board or both.

It's not that hard, it's just a pain...

That sounds about right.

I will try some newer devices to rule out any motherboard/components issues.

The Mac is 10 plus years old and who knows how many users.

It did come in the original box, that's a good sign.

I will try a few PCIe cards as well.

Unlike many others, I will post the fix when I find it.

Thanks for the help!