TX2i auto power on symptom.

Dear Sir.

We just got the TX2i module and tried to put on official carrier board.

When DC input, the system will auto power on and there’s no way to shut down system by pressing Power on button.

Do you have any suggestion for this symptom?


TX2i power on is level controlled with internal pull up instead of edge controlled. Pressing Power on button will not work for TX2i.

Thanks for your reply.

So currently on the B02/B04 carrier, there’s no solution to shut down the system?

You can try “sudo shutdown -H now” or “systemctl suspend”.
After that, you can power cycle to re-start TX2i.


Thanks for your reply.

I have follow your recommendation to test.

“Sudo shutdown -H now”

After running, the screen will be turn off but the Power LED still lighting.
Seems the system didn’t turn off. Press keyboard or mouse after couple of minutes, the system will auto power on.

“systemctl suspend”

Enter sleep mode.

Still can not shut down system.

Any recommendation?


Try lower case “-h”:

sudo shutdown -h now

There are actually a lot of ways to shutdown, and normally just hitting the power button is wrong (if it is set up to shutdown cleanly with power button, then this is the exception…systems which have a power supply which just turns off and does not cleanly shutdown should not do this unless there is a crash and there is no way to cleanly shutdown).

If the above doesn’t work, here’s an interesting URL on the many ways for shutdown on Ubuntu:

Have you guys read the TX2i datasheet? It specifically says that it will not let you to power it off and will automatically power on. If you need to power off, use a TX2.

We have TX2is and are aware the differences between TX2 and TX2i. To be able to correctly power on and off both TX2 and TX2i, carrier cards need to be redesigned to detect TX2 or TX2i and perform power on/off accordingly, e.g., to pull the power control pin low for shutting down TX2i.
There are reasons to use TX2is, e.g, to cold start at -40 degree C.
As mentioned in the posts above, to use existing carrier cards without causing files system corruption, the CPUs should be put to hold/shutdown state before power cycle.
As far as I can tell (from serial console output), the above mentioned methods did shut down the processes and close opened files.

I would like to design my own carrier board which able to support both TX2 and TX2i and I aware to the differences regarding the use of the power button and B48,B49 pins and the need to add some HW which identify what module type is running but still my question is:

Is it possible to auto power up TX2 or TX2i (without using power button) and then to power down using SW command only ? (again no use of power button at all time)