Nanos not auto-starting after being turned off for a longer period

I noticed by few Nanos B01 (as developer kit) that they do not auto-start after being off for a longer period (like e.g. for a few weeks)?
They all work through 4 Amps Waveshare’s power supply. Just after the barrel jack is reinserted once they continue to auto-start as before…
Why is this happening is there a way to prevent this ?
It is causing troubles when unattended devices are installed on remote locations…

Please if you could help and many thanks in advance…

Hi JoskoZadar,

Please check below items and try again:

  1. Plug-in microSD card
  2. Without a jumper on J48 pin.
  3. Plug-in microUSB connector on J28 pin to power on the device.

Thanks for reply,
I’m not sure do we understand each other, Nano should be powered through barrel connector (4 Amp mode) not microUSB one.
What do You point at with this solution ?

Hi JoskoZadar,

There are two methods can power on device: micro-usb connector[J28] and power jack [25].
Please reference detail from Nano User Guide.

I know there are two methods but why would I need to use microUSB if I have power jack already configured on all devices and microUSB method comes with decreased power/performance ?