I took out the pins without destroying the plastic. Isolated the pins with bits of tape and a lot of patients.
But nothing. Until I found this reply. So the pins need to go backwards then? Will try that.
One more thing. I don't have the green wire in my Asus TBex 3!
Mine goes (the large conector that came with Asus - from left to right):
1. Black
2. Brown
3. Red
4. Orange
5. Yellow
NOPE!! The PC won't turn on in my case if I reverse the order! It has a protection. I finally took out all the pins from the plastic connector and placed it in the motherboard aic. Booted into Windows, installed the drivers and the firmware and it works!
It found my UAD Apollo Twin connected via StarTech TB3 to TB2 adapter and plluged in the Asus TBex 3.
I isolated the pins with the tape so they don't touch each other and this is the pins numbering:
(just a notice, this is the thunderbolt aic connector on the board when you look at the board directly)
FROM LEFT TO RIGHT:
1. Yellow
2. Orange
3. Red
4. Brown
5. Black
In Windows it works, tomorrow I'll try playing with High Sierra because it wasn't recognized before I did the firmware update.
Also need to research the bios settings for Thunderbolt a bit.
P
.S.
Keep in mind this was me troubleshooting the Gigabyte Aorus Z370 Gaming 7 motherboard because in this motherboard the Thunderbolt aic 5 pin connector is smaller and the Asus ThunderboltEx 3 has a bigger (wider) connector.
So no need to destroy the plastic connector that the pins are located in. Just push them out, isolate them and plug in pin by pin using some tweezers, folowing the coloring numbers above.