I have intalled windows 10 in my NUC, then I installed linux in other partitions.
After that, I found that I can not enter bios or any operating systems.
I think that the bios may be broken, so I try to recover the bios.
However, I can not enter the power button menu. After pressing the power button for 3 seconds, there's nothing on the screen.
Sorry, my English is poor.
1. Press on the Power Button, until the Power Button LED changes its color from blue to amber. Now release the Power Button, after about 30 seconds NUC shall boot into Power Button Menu.
Try the following:
1. Connect headphones or amplified speaker to the front Audio Jack.
2. Press Power Button for about 3 seconds. The system will emit three short beeps from the PC speaker or headphones.
3. If you hear the third beep, release the Power Button - NUC shall reboot into Power Button Menu.
-If for some reason you have difficulty to boot into Power Button Menu, you may recover your Bios using Security Jumper method https://www.intel.com/content/www/us/en/support/articles/000005532/mini-pcs.html https://www.intel.com/content/www/us/en/support/articles/000005532/mini-pcs.html
If your system is not booting anymore, disconnect the connector of CMOS battery and reconnect it after 15 minutes. The battery connector is located near the SSD (on the right).
I recovered the bios using your method, then I can enter the bios. After that, I login the linux system, and the bios is broken again!
So I remove the bios security jumper in order to recover the bios, however, it did not work this time.
I can see nothing on the screen, nuc8 restarts automatically time and time again.
I'm sorry to trouble you again.
Only reconnect the battery and check if your NUC is working. If NUC is not booting, try to reach Power Button Menu first and try to recover bios again.
You probably are aware, that Linux in not supported O.S. for your NUC. I don't know how your Linux is installed (probably double boot?). I'm not expert in this area, however I think in this case it will be better to install Windows 10 and then run Linux using Virtual Machine.
I disconnected the RTC battery header for 25 minutes, then I connected it.
But nothing different, it did not work.
If I remove the bios security jumper, nuc8 restarts again and again, and I can see nothing on the screen.
If I replace the bios security jumper, I can login the linux system, but can not enter the bios.
1. No trouble at all. That is the purpose of this forum. As I've written in my previous post, I'm not familiar enough with Linux and with multi boot. However, at first, try to remove Linux and then try to install Windows 10, clean installation. If you machine is booting to Linux, why it will not boot from USB?
2. Some time, leaving the computer disconnected from power overnight (i.e. with Power Adapter cable disconnected from NUC), fixes boot problems.
3. If you remove the SSD with Linux installation, still the NUC reboots?
1 After started, NUC8 will enter linux directly, I can't see any other contexts. I can't enter bios, F2 or other key did not work.
So, I can't change the boot sequence, and it is impossible to remove linux and reinstall win10.
2 I will try this tonight.
3 I remove the SSD, the NUC does not reboot, but I still can't enter bios.
You can try one thing more:
1. Remove the SSD and the memory modules.
2. Power ON the NUC. The power button LED shall blink tree times.
3. If the LED blinks it means that POST is executed. Install only one memory module in the lower slot. Power ON the NUC again and see if you see the Intel logo.
I have tried, but the problem still exsits.
I guess that the UEFI loader wrote some wrong information in the NVRAM when I installed LINUX.
So I want to enter the UEFI shell to reset NVRAM data, but I don't know how.
I changed boot order using efibootmgr, set win10 to be the highest priority. So when I restarted the NUC, I entered win10 automatically every time.
Last night, win10 upgraded. This morning, when I restarted the NUC, I found I can enter bios...
I guess when win10 upgraded, the system reset the NVRAM data.
It seems that the problem has been solved, although I'm not sure of the real reason.