NUC7i5BNH : no display after bios setting change - constant reboots

[S1eepy]

Hello,

Last week, wanted to enable Legacy boot (in addition to UEFI boot).

Have been running proxmox without any issue o this NUC since 3+ years, NUC is running 24/7 with UPS.

After saving BIOS changes, it's impossible to see anything on the HDMI out. I had updated the BIOS about a year ago, and been running steadily ever since.

I have tried all what I have found on intel support site (BIOS power button, special boot & Clear CMOS using jumper, disconnect battery for some time, ...

The NUC constantly reboots, about every minute or so.

Not sure what to try next. Wonder how saving new settings in BIOS could cause this...

[n_scott_pearson]

Power the NUC off and then power it back on, holding the power button down for 3 full seconds and then releasing. After a short time, you should see the Power Button Menu appear on the screen. You can then use F2 to get into BIOS Setup (Visual BIOS), F9 to reset the BIOS Configuration and then F10 to save this configuration and exit. During the subsequent POST, you can use F2 to again enter BIOS Setup and make any changes required (Boot Order, etc.) or desired (disable NUMLOCK, etc.).

Hope this helps,

...S

[S1eepy]

Thanks Scott. Obviously I already tried this with no success. Nothing displayed on the screen. I'm using a screen that was working before with Visual bios. Tried with another screen too.

When I press the power button for 3 seconds, it briefly turns orange at some point, then I release but nothing displayed.

[n_scott_pearson]

Did you make any changes in the graphics configuration - perhaps increase the memory window size or reservation? These have been known to cause significant problems.

What you will need to attempt is to reinstall the latest BIOS using the jumper-based BIOS Recovery process. This is documented here: 

Intel NUC BIOS Update and Recovery Instructions.

...S

[S1eepy]

I had changed the graphics memory config about a year ago yes, because I wanted to use GVT-g.

But what caused my issue recently was to enable "Legacy bios" and I think I also enabled "Thunderbolt boot".

I made this change, saved using Visual bios, rebooted, and since then nothing displayed thru HDMI.

I have tried the jumper already, by removing it. Still nothing displayed at boot. Tried with 2 different USB keys, on both front & back USB ports.

I'm currently trying (again) to unplug the CMOS battery for some time to see if it works. It has not the first couple of times I tried it. Will let it unplugged for several hours.

[LeonWaksman]

Since you enabled legacy boot, you may want to try iflash BIOS update with BNKBL357.86A.0083.BI.zip. You should use DOS bootable USB stick. Please read the instruction for iflash update in BIOS Update Readme

Leon

[S1eepy]

Thanks Leon. I created a bootable disk using rufus. But nothing really different from before.

Seems my situation is really similar to this one: https://community.intel.com/t5/Intel-NUCs/NUC7i5BNH-Bios-update-failed-now-cannot-boot/m-p/581858

Except I ran into this by simply changing BIOS setting and not trying to reflash.

[S1eepy]

I am now seeing this kind of behaviour, with reboots every minute or so. Not sure what this type of blinking led means. I don't see it in the list of LED blinking patterns:

https://drive.google.com/file/d/1iU6uTz6v4UzgguSH_XbYEJe2LjDWifwK/view?usp=sharing

Plus nothing displayed.

[LeonWaksman]

Did you tried to power ON your NUC with the BIOS Security Jumper removed and with empty USB ports (you may leave the kyboard+mouse connected)? NUC should boot into Configuration Menu after about 30-60 seconds.

Leon

[S1eepy]

Thanks for your help @LeonWaksman .

When I try this (boot with no sec jumper and nothing on USB): I press the power button, the NUC boots and then about 77 seconds later, it reboots. Then stays on forever. Nothing displayed on HDMI. Tried several monitors, including one which was working with visual bios before.

I also tried with jumper on pins 2-3: I see more activity there, especially on the blue led rectangle. But still nothing displayed.

Not really sure what to do next. I don't understand how Intel bios can be so buggy. I simply modified one or two settings and since then computer has not displayed anything. I have contacted customer assistance, and they tell me that warranty has expired, and they cannot do anything for me. I really don't understand.

[LeonWaksman]

Hi @S1eepy 

I agree with you that changing parameter in BIOS, should not outcome with NUC bricked. Try to reset BIOS using "blind" method:

1. Power on your NUC and after 5-8 seconds, repeatedly click on F2.

2. Continue to click on F2 5-10 seconds more or stop it if you see that the Power Button LED blinking stopped.

3. Next click on F9, wait 2-3 seconds and click on "Y".

4. Finally click on F10, wait 2-3 seconds and confirm with "Y". 

Good luck

Leon

[S1eepy]

Thanks, had seen that in other threads (like here: https://community.intel.com/t5/Intel-NUCs/NUC7i5BNH-Bios-update-failed-now-cannot-boot/m-p/581862/highlight/true#M52264)

Tried, but with no luck unfortunately.

Power button doesn't blink. Stays on until automatic reboot after roughly 1 minute. I have the sec jumper installed in pins 1-2.

The power button does not blink: I plug power, it turns orange. I press on it, it turns blue, and so does the rectangle blue led, and then the NUC reboots every minute or so. I tried with & without mSATA SSD.

[LeonWaksman]

One thing more, try again to re flash BIOS using iFlash USB, but this time, with System Drive removed (the BIOS jumper between pins 1-2). Save the IFLASH2.exe and BN0083.bio files on the bootable USB and add autoexec.bat file (attached) containing command:

IFLASH2 /pf BN0083.bio

Leon

[ClariceStarling]

If he made a recovery usb when his computer was new, couldn't he just use it now .. unless he doesn't want to wipe everything off?

[LeonWaksman]

Hi @ClariceStarling 

You mean to boot from the recovery USB in order to re-flash BIOS? The problem we have here is with the BIOS, rather than with the OS. So, bootable USB is good enough and recovery USB will not help more.

Regards

Leon

[S1eepy]

Hi @LeonWaksman : tried what you suggested last, without success. Even tried with a new usb key, smaller (only 4GB).

@ClariceStarling not sure what is recovery usb? something related to windows (which I don't use). Problem is not about loosing data (everything is backed up), but simply booting the NUC and have something displayed.

[S1eepy]

@LeonWaksman or @n_scott_pearson  : can you help me identify this blinking LED pattern in this video: https://community.intel.com/t5/Intel-NUCs/NUC7i5BNH-no-display-after-bios-setting-change-constant-reboots/m-p/1284901/highlight/true#M83483

I think I understand thermal issue, but not sure. Is this continual blinks or 16 on/off ?

https://www.intel.com/content/www/us/en/support/articles/000005854/intel-nuc.html

If continual blinks, means BIOS is being updated? However, I don't see the USB key led blinking, means no USB activity happening.

I have tried to put jumper to positions 2-3, then power on. I'm looking for a way to reset BIOS settings to default.

Should I try with older BIOS version?

Forget this question: "Known Errata: Due to the Intel® ME firmware update in BIOS version 0083, you can’t downgrade to version 0082 or earlier."

What happens if I try to update BIOS with the other methods (power-on button, ...) and the BIOS already has the version I am trying to flash? Is it overwriting the existing BIOS?

thanks

[LeonWaksman]

1. I can't identify the pattern. It is 15 blinks ON/OFF and than OFF for three seconds and blinking again. This may be BIOS update pattern but certainly not CPU Thermal trip warning, where the blinking should be in higher frequency (0.25 seconds ON, 0.25 seconds OFF for total 16 blinks) and then computer should be OFF.

2. You should not try to update BIOS with jumper in LOCKED position (2-3). 

3. Try to update  BIOS  by BIOS Recovery by BIOS Security Jumper Removed. This should unlock the Management Engine Firmware:

3.1 Prepare USB stick fully formatted to FAT32 . Format your USB with Quick Format option unchecked. Do not format your USB in MAC (OS) or Linux machine. Use Windows. Download the BN0083.bio file. Copy the BN0083.bio file to the root of this USB.
3. Disconnect the power adapter and remove the bottom panel from your NUC.
3. Remove the Yellow Bios Security Jumper. (page 59 in Technical Product Specification)
5. Insert the USB with the BN0083.bio file into rear USB slot.
6. Reconnect the power adapter and power ON the NUC. Wait 30 sec - 2min. The Recovery process will start automatically and will end after 2 -5 minutes.
7. When bios recovery is completed, press and hold the Power Button to switch the power OFF, remove the power adapter and replace the Security Jumper (pins 1-2) . Reinstall the bottom panel.
8. Power your NUC ON.
9. Enter Bios setting by pressing F2 during boot process.
10. Press F9(followed by "Y"), to set Bios to default settings. Press F10 (followed by "Y"), to save the settings and exit to O.S. Let the NUC fully reboot.

If the above process was completed successfully, you need update BIOS again, but this time using the F7 method. Only then the Management Engine and EC firmware will be updated:

1. The same USB stick with the BN0083.bio insert in the rear USB slot.

2. Power ON your NUC. 

3. When you see the Intel NUC logo, repeatedly click on F7. Update Menu will appear.

3. In the update Menu click on line with your USB (probably Mass Storage Device), and then click on line with BN0083.bio. The update should start.

4. When the update finishes, NUC will restart.

But I understand that the chance that the above procedure will work is low. However I don't see any point or advantage to downgrade the BIOS. However if you decide to do this, use the Recovery Method by Security Jumper Removed.

Leon

[n_scott_pearson]

To me, this looks like a heartbeat and not a flashing signal at all. Still, I would proceed with Leon's suggested update process.

...S

[S1eepy]

Thanks guys.

Well I tried this, but unfortunately with no luck. Display remains off all the time.

When I boot without jumper & USB key in rear port as suggested, there is some brief (5-10 secs) activity on the USB key.

After 7-8 mins, I manually power off, then replace the jumper and reboot. But then the NUC enters this infinite boot and has this undocumented power LED pattern. Reboots occur roughly every minute.

I tried the blind F2/F9-Y/F10-Y, however no success.

On the root cause side, trying to understand why I face such issue: I was wondering if it's normal to be able to enable both UEFI and Legacy boot in the BIOS at the same time. Because it seems to me it's what caused this issue. I think I also enabled something related to Thunderbolt, however not really sure about setting naming. Then simply saved setting and reboot. Since then, facing this nightmare

[LeonWaksman]

Sorry to hear this.

Yes, it is possible in your NUC to enable UEFI and Legacy boot simultaneously (the Secure Boot have to be disabled). If both UEFI and Legacy boot are enabled, the computer will attempt to boot from UEFI boot before booting from the Legacy boot.

Leon