10 Replies Latest reply on May 31, 2017 3:12 PM by lw1948

    NUC7i5BNK power led not working

    ivrom

      Hello,

      My new NUC7i5BNK has power status issue. By default power button's LED shows current power status (blue/amber light) but mine NUC7i5BNK stays dark regardless of power status. If Power button's LED is configured to display HDD activity, it does it as expected. LED ring also able to display HDD activity, but configured to show power status it stays dark. This indicates that both power button and ring LEDs and connectors do work,  where power status controller does not work as expected. I tried to reset/update BIOS and this had no effect.

      I ordered two identical sets of NUC7i5BNK , M.2 drive, memory. One has power status issue, another one works as expected. BIOS versions and settings on both are the same. BIOS version is the latest (version 46).

       

      Is there a chance that this is not a hardware issue? If so, how may I diagnose and fix it? It would be very unfortunate to replace a NUC because of faulty power led controller.

       

      On top of power status issue, both NUCs have random (?) boot issue (no video). Power off + 3 sec power button hold does invoke recovery menu as expected. It boots always after that (say if normal boot selected). I think this issue mostly (only?) happens if I unplug power supply. Any clue how this could be fixed?

       

      Thank you very much for your help!

        • 1. Re: NUC7i5BNK power led not working
          lw1948

          1. In order to fix power led indication, remove NUC bottom cover and check if the Front Panel connector (connector A on the attached image) is sitting firmly in its receptacle. The bios shall be set to default.

          2. In order to get Power Boot menu, you shall release the power button before the 4-second shutdown override.

          Push the power button and hold it down for 3 seconds. The system will emit three short beeps from the front panel (FP) audio port (if you have connected speaker), then you shall release the power button. The FP power button LED will also change from Blue to Amber when you can release the power button.

           

          Leon

          • 2. Re: NUC7i5BNK power led not working
            ivrom

            Hello,

            1) Unfortunately this does not work. I specifically indicated that power button and ring both correctly blink on HDD activity once they configured to show it. This 100% proves that leds and connector do work. They do not show any change in power status though;

            2) I did not have troubles how to invoke boot menu. Unfortunately there is no explanation why NUC may not boot after power disconnect.

             

            Mystery with power led is still there. Any other clue?

             

            Vyacheslav

            • 3. Re: NUC7i5BNK power led not working
              Intel Corporation
              This message was posted on behalf of Intel Corporation

              Thank you very much to for the suggestions posted above.

              Hi, , Thank you very much for joining the Intel® NUC communities.

              Besides trying the steps above, in regard to the problem with video not showing randomly, we recommend to use high quality HDMI cable, please make sure the version of it is 2.0a, even though it is happening on 2 different NUCs the problem could be related to it, also make sure it is properly attached and the BIOS is set to defaults.

              To answer your question, yes, the problem with the indicator power light could be a hardware issue, specially as you mentioned, that it is happening only with 1 of the 2 NUCs, please try to re-install the graphics driver, 4627:
              https://downloadcenter.intel.com/download/26480/Intel-HD-Graphics-Driver-for-Windows-10-for-Intel-NUC-Kit-NUC7i3BN-NUC7i5BN-and-NUC7i7BN?product=95061

              To replace the NUC, you can get in contact with the place of purchase and depending on their warranty they might be able to replace it for you. Or remember that the Intel warranty is for 3 years, so we can do that for you as well. Please let me know the results of trying the steps above and if you are interested in replacing the NUC directly with Intel.

              Any further question, please let me know.

              Regards,
              Alberto R

              • 4. Re: NUC7i5BNK power led not working
                lw1948

                Hello Vyacheslav,

                In my understanding HDD drive activity led (in the Power button) and the Power led are two separate led. The first is connected to pins 1-3 and the Power LED is connected tp pins 2-4 on Front Panel Header. So, if the HDD drive activity LED is functioning it doesn't prove that the Power LED is connected. Any way since you wrote that both your NUC units have same bios and in the same configuration (the Power LED function is controllable in bios), probably it is a hardware failure and you shall ask for replacement.

                 

                Leon

                • 5. Re: NUC7i5BNK power led not working
                  ivrom

                  Thank you for your suggestions!

                   

                  To continue unit debugging I brought NUC to the work place. It welcomed me by power LED upon boot up! So, it was disconnected from a power supply overnight and started to work this morning on the very first boot.

                  Sorry to say this, but this likely indicates some sort of design flaw (inability to properly reset states?). Looks like some registers do reset to some random inconsistent state upon power disconnect or on some other event and stay this way even on power disconnect for a very long time because of some sort of capacitor on a power bus. BIOS reset to default state did not help.

                  I have seen not quite but still similar issue on previous gen NUC5 when IR controller did not work out of the box under linux. Installing IR controller driver under windows fixed thing (how this may ever help? I guess driver just set some registers to the correct state, but it is just a speculation). BIOS reset did not help as well.

                   

                  I count that problem as solved. But I guess it is just a time bomb waiting for other occasion to return.

                   

                  Intel, please look closer into power up consistency. I'm as radio engineer feel that there is something may not be right with unit init. May be too much (init) logic was offloaded to the software? NUC is an excellent piece of engineering, lets make it just perfect!

                   

                  Thanks a lot!

                   

                  Vyacheslav

                  • 6. Re: NUC7i5BNK power led not working
                    ivrom

                    HI,

                     

                    There is no separate HDD activity led on the NUC7i5. There are power and ring LEDs only which may be used in multiple roles. They connected to the PCB with 4 (?) wire connector. There are just not enough conductors to support more than 2 LEDs (without a controller on a front panel, which is overkill). I'm not even sure how color changing logic was implemented using just 4 wires (may by reversing polarity?).

                    So if the same LED does indicate HDD activity and does not work to show power status, I count this as a 100% evidence that LED itself and connector do work.

                     

                    Unit starts to work after sitting without power overnight. Disconnect for say 10-20 minutes (likely for much longer) did not help. Overnight wait fixed things.

                     

                    Anyway thanks for your hints.

                     

                    Vyacheslav

                    • 7. Re: NUC7i5BNK power led not working
                      lw1948

                      Hello Vyacheslav

                      1. I'm glad that your NUC works now like you have expected.

                      2. According to your NUC specification, there are separate LED for HDD activity and for Power. They are connected to connector A I(see the image I've attached in post #1.  In addition there is ring LED connected to connector C (ref. to the same image above.

                      3. See the attached pages from specification showing the LED connections.

                       

                      Regards

                      Leon

                      • 8. Re: NUC7i5BNK power led not working
                        Intel Corporation
                        This message was posted on behalf of Intel Corporation

                        Thank you very much to for the comments provided previously.

                        Hi It is great to hear that you found a work around in order to use the NUC and the indicator lights properly. Also, I will send your suggestions to the proper department for them to be aware of your comments.

                        Any questions, please let me know.

                        Regards,
                        Alberto R

                        • 9. Re: NUC7i5BNK power led not working
                          NucC7I5BNK

                          I have the same symptom: brand new C7I5BNK unit, latest firmware (BN0046.iso), only power LED works when set to show disk activity.  Border LED never does anything.  Tried all settings, set to default, reapplied firmware.  Any suggestions?   FYI A connector in my unit is an naked pin - there is no cable attached to that PIN.  Setting it without power doesn't remove the symptom in my case. 

                          • 10. Re: NUC7i5BNK power led not working
                            lw1948

                            Try my answer #9 here: Re: NUC7I5BNH LED ring does not work after updating BIOS

                             

                            Hope this will help

                            Leon