Setup (F2 at powerup) shows Batt icon with 00% and "Not installed" message below this icon.
Also, "AC Adapter = 45w"
So looks like I have to send it to service.
If you're comfortable opening the computer, I suggest removing battery and then press and hold power button for 30 seconds as you pointed out as one of the troubleshooting steps in your post. Before opening the computer case and removing the battery, please read the service manual thoroughly in link below.
I manged to transfer the warranty via DELL from the US to my country.
Yesterday I sent my laptop to the lab for repair.
Hope to have it running (for the 1st time since purchase…) next week.
Thanks for the support.