how to reset PRAM in the Mac Pro 7,1?

• I looked at your reference link. It says "On Mac computers that have the Apple T2 Security Chip, you can release the keys after the Apple logo appears and disappears for the second time. "

Well this computer does indeed have the T2 chip. The apple logo only appears once.

Are you saying that if I continue to hold the keys down after it completely boots the first time, the thing will reboot again?

That's not working. I press the keys immediately after pressing the on button.

The computer boots the same if I hold the keys or not. The apple appears, the horizontal thermometer makes its way across beneath the apple and the the screen background with all the icons appears. Apps which were active before shutdown reappear and open.

Are you saying if I keep on holding the keys after all this happens, the NVRAM will be reset?

I tried with the 7.1 keyboard wired directly to the PC's USB port. No joy.

Then I tried a keyboard - USB only - from a Mac Pro 5.1. Still no joy.

Tried each one twice without any results other than a normal boot.

So I ran the Terminal command nvram -c. No way to tell if it worked...

NOT SOLVED.

I tried to choose another response and the thing marked the problem solved when it is definitely NOT solved...