Shutdown then Immediately Restarts

I used Etcher to burn KNOPPIX 8.1 CD/DVD to a USB drive. Booted to it and got the system to come up. Boy, KNOPPIX does not like 3840 x 2160 resolution! I had to grab a pair of magnifying glasses I use for circuit work to be able to read the menus.
I am comfortable with ubuntu but know little of KNOPPIX. I could not find how to shut it down so I opened a terminal and issued sudo shutdown -hP now. That worked and I heard "Initiating Shutdown" in the spacey, female voice.
The system shut down and then restarted.
Did I write the correct command or does KNOPPIX need something special to issue a full shutdown?
Gack!

Try below command:

Code:

shutdown -h now

If above command wont work try below suggestion.

1. Click the “K” menu in the bottom left corner.
2. Click “Logout”.
3. Knoppix will begin shutting down.
4. The Knoppix CD will be ejected.
5. Remove the CD and close the tray.
6. Press Enter on the keyboard.
7. Knoppix will attempt to turn off the computer automatically. If it doesn't turn off automatically, it is now safe to turn off the computer yourself using the power button.

Had to use the K menu to initiate shutdown.
As before, the screen reports the system shutdown and then the computer restarted.

Please upgrade BIOS firmware with latest version of the BIOS firmware. You can download latest version of the BIOS firmware from your computer manufacturer website.

If something goes wrong, it could render the PC completely unbootable; you won't even be able to boot a live Linux flash drive or reinstall Windows. There's probably a way to bring the PC back to life, but it won't be easy. Normally one should not really update the bios unless you are experiencing issues which a newer version address, which appears to be the situation in your case.

I'm going to perform another full backup before updating the BIOS. It's odd that HP's own Support Assistant does not pick up on the BIOS update ver F.30A (I'm running F.21). The Readme for the update package states it's for Win 10 1709 update issues. 1709 hit my system last week just before all of this madness...

Successfully updated the BIOS but that did not fix the shutdown = restart problem.
1. Windows displays this issue.
2. KNOPPIX displays this issue.
3. After updating BIOS it still has the issue.

ghanson said:

Successfully updated the BIOS but that did not fix the shutdown = restart problem.

Hi, my understanding is that you unplugged ALL the peripherals, right?
Maybe the problem is with a mechanical part of your laptop, like the power-on button.
The third thing that comes to my mind is the faulty power supply, so I would unplug it and use the batteries only (just once, to exclude even the least probably causes).
And lastly I would update the GPU's drivers (directly from the producer's site).

I spent two hours with elevated Tech Support at HP and they're having me send the system to Repair.
We ran through resetting BIOS, updating BIOS, resetting CMOS, various boots with/without peripherals. The Tech was actually quite knowledgeable and did not treat me like an idiot (you know, "Did you press the power button to turn on your computer?")
Another owner of this model had the same issue and posted on the HP forums that he had to send it to Repair and the motherboard, graphics card and power switch were all replaced. His computer was one model series before mine but some of the hardware components are probably the same.
I'm going to leave this thread open until the system gets back from HP. I'll report the fixes here to close the loop.
Thanks everyone for the guidance and help.

Run this log collector and post a zip into the thread for troubleshooting:
log collector v2-beta06.zip

Open the HP website > software and drivers > enter the computer's product or serial number > enter operating system > view drivers > post a URL or hyperlink into the thread.
HP Software and Driver Downloads for HP Printers, Laptops, Desktops and More | HP® Customer Support

Just a thought, if you are connecting via HDMI. do you have CEC enabled on the bluray player. If so, this may be causing it to restart. To test disable CEC mode.