5 Replies Latest reply on Feb 6, 2018 9:15 PM by N.Scott.Pearson

    "External" drive connects/disconnects


      I have an NUC5CPYH has a problem with the computer detecting and then losing this drive with the constant connect/disconnect tone from the front panel.


      I did use this drive in the NUC for a short time before replacing it with an 120GB SSD and 8GB RAM.


      My intention is to use the drive as a backup for this unit.


      I have is with a recovered hard disk (Toshiba model MK2555GSX), a 250GB disk recovered from a laptop enclosed in a Inateck 2.5" SATA to USB3.0 output.


      On a traditional desktop Dell Optiplex 780, it has not issue of connecting/disconnecting and it performs flawlessly.


      My 2 questions are:

      Does the NUC not put out enough power to spin the drive so it stalls/starts repeatedly?

      Does this drive require more power than others? (A Canvio 1TB 3.0 external drive does work without any issue)

      Thank you in advance for your comments.

        • 1. Re: "External" drive connects/disconnects

          The power requirements of the Toshiba MK2555GSX drive, at 1.0A, is very high for a 2.5" drive. This is higher than the 900mA provided by standard USB 3.0 ports.


          Does the drive operate more consistently when the unit is plugged into the yellow USB 3.0 charging port on the front of the NUC5CPYH? This port makes 1.5A available and should be able to better handle this drive. If it does not, then the issue is not power related.



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          • 2. Re: "External" drive connects/disconnects

            I did try the yellow port prior to reading the reply and it worked flawlessly.


            I looked for the power draw online for that drive and didn't find it.


            Is the 900mA & 1.5A output standard on all NUC's?


            Thanks again...

            • 3. Re: "External" drive connects/disconnects

              Yes. These are the power supply requirements proscribed by the USB standards. For more information, consult the USB page in Wikipedia. There is a table in the Power section that details what the various types of ports are required to supply.


              I simply googled for the drive's requirements. The 1.0A requirement (which I presume is the startup requirement) is *significantly* higher than any other 2.5" drive that I have looked at.



              • 4. Re: "External" drive connects/disconnects

                Craziest thing is that having no trouble with the yellow USB port, I tried it as a media storage for OSMC  for a Raspberry Pi 3b.


                It works flawlessly and doesn't have the issues when I first started trying. So then I connected it to the back of the NUC and it connected once and is in standby at this moment.


                Maybe it "stuck" and was drawing too much current and now it "knows" better.


                Any thoughts to see if the problem will and should reoccur?

                • 5. Re: "External" drive connects/disconnects

                  USB 3.0 ports are required to provide 900mA of power. Some designs provide more, some don't. It looks like the NUCs don't.


                  Remember, if the USB port is only providing the basic 900mA and the drive tries to draw 1000mA while starting (spinning up), there is a chance of it hanging as a result. If your have drive is being allowed to spin down when idle, then the hard draw for spin up is going to occur again and again - and could eventually fail is this is borderline.


                  I would stick with the charging port,