You are supposed to power off and unplug power, install a jumper, power on, let BIOS complete POST, power off and unplug power, remove jumper and then power on again. Is this what you did?
That's the process for CMOS reset. The MBEX reset (which seems to have triggered this problem) is:
2.4 Intel® Management Engine BIOS Extension (Intel® MEBX) Reset Header
The Intel® MEBX reset header (see Figure 13) allows you to reset the Intel ME configuration to the factory defaults. Momentarily shorting pins 1 and 2 with a jumper (not supplied) will accomplish the following:
• Return all Intel ME parameters to their default values.
• Reset the Intel MEBX password to the default value (admin).
I can't get a CMOS reset to work at this point - I don't think I am even getting to that part of the POST (fan doesn't power on, for example) but rather I'm stuck in a Management Engine POST subroutine...
Some comments in-line
- Power off completely (unplug from wall). Done
- Place a jumper across pins 1 & 2 of the MEBX Reset header. Done
- Make sure the yellow jumper is on pins 1 & 2 of the BIOS Configuration header. Done - normal running state
- Remove the CR2032 Battery from the board (this is the battery that maintains the state of the CMOS). Done
- Wait 15 minutes. Done - in fact this wait was over the weekend
- Power on the system. Done
- Wait for BIOS (and ME) to complete their POST processing (worst-case should be ~15 seconds).
I end up in the blink code / error state described in this thread.
8. Power off system completely.
9. Remove the jumper from the MEBX Reset header.
10. Power on the system.
11. If, during POST, you see a message saying CMOS Battery Failure, you need to go into BIOS Setup and set the date and time. Make sure you exist BIOS Setup with a save of the BIOS Configuration.
Keep going; what happens at that point doesn't matter (the reset should have occurred)...
Thanks for sticking with me on this Scott
There is no "keep going" - the LED light is either solid on (with nothing ever appearing on the screen, even overnight), or when I press the power button it goes into a 0.5s on / 5.0s off cycle (overnight). It never gets into BIOS, the fan doesn't power on...when I take out the memory and try to power on, I don't get any beeps or anything...
The MEBX reset procedure seems to have trapped 3 out 5 Horse Canyon NUCs in this state of limbo (2 of 5 NUCs, the same reset process worked). They must be stuck very early on in a POST sequence...I'm just flying utterly blind and haven't been able to figure out a sequence that gets them "unstuck."
Are you using the latest BIOS 0043? I tried the procedure on my RK NUC board and it cleared the MEBx settings fine. One thing that Scott was incorrect on is when you jumper the MEBx pins 1-2, make sure AC power is removed first. Do not remove the battery when doing this either. Remote power jumper 1-2 on MEBx header, remove jumper, connect AC power, power on system, let it boot through POST once completely.
Your MEBx settings should be reset and the system will boot fine then.
No, I wasn't incorrect. What part of "1. Power off completely (unplug from wall)." didn't you get?
The placement of a jumper on the MEBX Reset header can cause corruption in the CMOS. I included the removal of the CR2032 battery in the process to ensure that the CMOS is cleared completely. This is a safety measure...
So I think this is basically the problem - given that I followed the documented procedure (unplug from power, simply short 1&2, plug in) initially...when you follow the same procedure on 5 machines and three of the five behave differently than the other two it certainly "smells" like some sort of state / software issue.
None of the attempted recovery steps (including wiping CMOS via long disconnection from power and using the CMOS reset) have been able to recover.
My guess is that had I followed Scott's instructions from the start (rather than the documentation) I might be in a better place?
@Mitch - I'm not sure what BIOS level it they are at since they won't even boot into BIOS :/ It's entirely possible that the documented procedure works on newer NUCs - I think this was the first generation of NUC with vPro/AMT...
I was talking to MrMitch offline to see why he thought I was wrong - and discovered that he is right! Unfortunately, I started this investigation looking into a similar issue reported against one of the older Intel Desktop Boards. Its TPS' wording threw me off completely and I made the bad assumption that the process I read would be the same for the NUCs as well. Two wrongs don't make a right; two wrongs make a worse wrong...
Ok, after we re-read everything, here is the correct process:
- Power off and unplug system.
- Place a jumper on the 1-2 pins of the MEBX Reset header.
- After ~5 seconds, remove this jumper.
- Power on the system.
- Wait for the system to complete POST (the actual application of the reset occurs near the end of POST).
Regarding your (AgentP's) issue, I sent a note to the sustaining engineers and they are going to have someone look at the RK BIOS and see if they can sort out what is going wrong and how to recover...
Sorry for my brainfarts...
Yep so that's basically the documented process - though the ~5 seconds is a better description of "momentarily" than leaving it as an exercise to the reader. I had them jumped for about a second. Perhaps the root of the inconsistency...
Hi N. Scott Pearson,
I have tried your instructions and am still stuck in the 0.5s on / 5s off loop. Was their any info from the engineers on how to fix this?
Thanks in advance
The standard things to do in this case are to (1) clear CMOS, (2) reset MEBX, (3) attempt to reinstall the latest BIOS using the recovery method. Does anyone else (Intel contingent) have any other ideas?