Apple Thunderbolt Display won't turn on automatically after updating BIOS

[acidrums4]

Greetings,

Last year I got a HP 800 G4 SFF. In adition to an Apple Thunderbolt Display, I got an HP 4CX35AA PCIe card (from here) which after a long shipping wait and some little bumps and hiccups (and an Apple Thunderbolt 3 to 2 adapter), let me use it in all of its glory - not everything perfect actually: when power settings turned off the screen, at random times it refused to turn on again. Could not debug or troubleshoot that issue.

Now, it was only until past sunday I figured out I could update the BIOS from itself, network connection provided. It had 2.14 and updated to 2.17.

After that, the display refused to power on automatically. No HP bootup logo. Nothing.
Did a BIOS reset - nothing.
Went back to BIOS 2.14.1 - nothing.
Disabled power options on the bios - nothing.
Since is my only monitor, it's becoming utterly annoying since I have to first connect the PC to the TV via a DP-HDMI adapter which the PC will use as its main display; the bootup process happens and finally the Apple Display will start working when the bootup process reaches the desktop.

Any ideas about how to troubleshoot this, or what is even happening here? Thank you.

[erico]

The simplest troubleshooting tests will be to:

a) try a different display with your PC

or

b) take the Apple display and connect it on a different PC to verify that it is still operating as it should.

c) test the HP Thunderbolt PCIe card  and the Apple display with another PC.