8 Replies Latest reply on Jul 9, 2015 11:54 AM by malanisibm

    D525mw issues with auto power on after power failure on BIOS v113 and v132

    malanisibm


      Hi,

      We are facing an issue where only some of our systems are not self powering on after a power failure on a fan-less PC, the BIOS setting in set to 'power on'.

      Some observations to share:

      a) Initial CMOS Battery levels on a couple of systems showed to be 2.5V, 1.9V and 1.0V

      b) Replacing the CMOS battery seems to resolve the issue.  When the CMOS battery level is at 2.5V or above the issue seems to get resolved(at least with initial testing), not sure if the issue can return later.

      c) Also reflashing the BIOS (Provided by Intel via our PC manufacturer) with same version(113) or above (132) resolves the issue only with a new CMOS battery or a >2.5V CMOS battery.

      d) Reflashing with a <1V CMOS Battery does not resolve the issue.

       

      The units were running 24-7 environment prior to a power failure (power cycle) and only some did not powered back on.

       

      The question that we are trying to find some answers to is:

      1) We would like to know what is the relationship of the CMOS Battery level and the system not being able to 'power on' after a power failure.

      2) The D525MW user manual mentions the BIOS settings being stored in SPI flash, which I probed the pins to see who supplied power to it and it seems to come from the board supply and not the CMOS Battery, if not powered from the CMOS Battery, then why is there some type of impact when the battery is very low?

       

      It is not possible to fully duplicate the issue on one of units unless we put in a very low level <1V battery.

      Any help or guidance is appreciated.

        • 1. Re: D525mw issues with auto power on after power failure on BIOS v113 and v132
          hansb_intel

          Hello Hello malanisibm,

           

          Please check the answer to your questions below:

           

          We would like to know, what is the relationship of the CMOS Battery level and the system not being able to 'power on' after a power failure?

           

          If the battery power is too low and you have a power failure, the BIOS would go back to default settings, the default settings most likely are set to “stay off” after power failure. The PC manufacture could have changed the default setting through the SPI flash so you would need to check with them to see exactly what the default setting would be. If they are set to “stay off” then you may be able to change it to “stay on” or “last state” if this option is available to you in the BIOS, but this would be stored in the CMOS memory  as “custom default settings “which requires the batteries’ power to store the settings.

           

          The D525MW user manual mentions the BIOS settings being stored in SPI flash, which I probed the pins to see who supplied power to it and it seems to come from the board supply and not the CMOS Battery, if not powered from the CMOS Battery, then why is there some type of impact when the battery is very low?

           

          Similar to the first answer, the SPI contains the basic setup information, but all custom settings are stored in the CMOS RAM. if this information is set to “stay off” by default; this is what is going to happen when power comes back. The only way to prevent this is to have a properly charged battery to maintain custom default settings.

          • 2. Re: D525mw issues with auto power on after power failure on BIOS v113 and v132
            malanisibm

            Hi hansb_intel,

             

            Thanks for your prompt response. Here are some follow up questions.

             

            We would like to know, what is the relationship of the CMOS Battery level and the system not being able to 'power on' after a power failure?

            If the battery power is too low and you have a power failure, the BIOS would go back to default settings, the default settings most likely are set to “stay off” after power failure. The PC manufacture could have changed the default setting through the SPI flash so you would need to check with them to see exactly what the default setting would be. If they are set to “stay off” then you may be able to change it to “stay on” or “last state” if this option is available to you in the BIOS, but this would be stored in the CMOS memory  as “custom default settings “which requires the batteries’ power to store the settings.

             

            [maalanisibm] Are the PC manufacturer's default settings changeable in SPI Flash by simply reflashing a new/different BIOS version w/this setting to 'power on'.  The current default setting that we see on the BIOS Setup initially when we re-flash the BIOS version is set to 'Power on', but when we have a low battery or no battery the system behaves as if it is set to 'stay off', but if we put a good battery+manually power on(button) first time and then cut the AC power the system will 'power on'.

             

            The D525MW user manual mentions the BIOS settings being stored in SPI flash, which I probed the pins to see who supplied power to it and it seems to come from the board supply and not the CMOS Battery, if not powered from the CMOS Battery, then why is there some type of impact when the battery is very low?

            Similar to the first answer, the SPI contains the basic setup information, but all custom settings are stored in the CMOS RAM. if this information is set to “stay off” by default; this is what is going to happen when power comes back. The only way to prevent this is to have a properly charged battery to maintain custom default settings.


            [maalanisibm] We would like to be able to have the default information in SPI set to 'power on' by default, w/out having to change batteries in the field to overcome the problem, in other words a potential SW workaround.


            I ran into this Intel page (Desktop Boards — CMOS Battery) and have some new questions with the terminology to keep things straight w/this trail and that page.

            CMOS RAM- ?

            CMOS SRAM- ?

            SPI Flash- ?

             

            And, were are the Default BIOS settings, Custom BIOS settings stored in these memories?  Is there a ROM type BIOS setting as well that the system defaults to?


            Also is there some type of mux in the motherboard that determines which BIOS to run at power on weather it has a good battery, low battery or no battery)?


            Thanks for all your help in advance.




             

            • 3. Re: D525mw issues with auto power on after power failure on BIOS v113 and v132
              malanisibm

              Hi,

              Please let us know if you have any updates to my followup questions.  This is a very urgent matter as we need to identify all possible solutions to this problem.

              Thanks for all your help.

              Miguel

              • 4. Re: D525mw issues with auto power on after power failure on BIOS v113 and v132
                hansb_intel

                Hello Miguel,

                 

                We have escalated your questions to our engineering team; we will provide the answers once we get them from the engineers.

                 

                Regards

                Hans

                • 5. Re: D525mw issues with auto power on after power failure on BIOS v113 and v132
                  malanisibm

                  Thank you so much Hans, keep us posted as soon as you hear back as it is a pretty urgent matter to us.

                  regards,

                  Miguel

                  • 6. Re: D525mw issues with auto power on after power failure on BIOS v113 and v132
                    malanisibm

                    Hi Hans,

                    Just touching base to see if there are any developments with engineering?

                    thanks,

                    miguel

                    • 7. Re: D525mw issues with auto power on after power failure on BIOS v113 and v132
                      hansb_intel
                      1. nothing yet, I'll check with them again to see if they have any updates.