Power LED blinking meaning?

Hi, I’m trying to debug why my Nano randomly shuts down, and I’m trying to investigate if it’s power related. The nano is powered through the two 5V GPIO pins from a 5V voltage regulator with a 4% accuracy.

Several questions:

  1. I notice that the power LED blinks. Is this normal? I couldn’t find any documentation as to whether this has a semantic meaning
  2. I’ve measured the current going into the Nano, and I see only about ~0.3-0.5A even when the nano is in jetson_clocks mode at MAXN. When I stress test the CPU, I get about ~1A of current draw. Is this normal? I’ve also verified that POM_5V_IN from tegrastats shows appx the same readings in terms of wattage at 5V.

Is there anything else I should look into?

A simple way is to compare to the test result with DC jack power supply. If no random shut down with that, then it might mean the issue of power thru GPIO pins. And if it is power supply related issue, you should be able to capture voltage drop on 5V rail with oscilloscope.

Could you please answer the two questions that I had?

Power LED should be ON not blink, the power of stress depends on use case. The key point is random shutdown as you said, that’s obviously abnormal.

Okay, but the blink must have semantic meaning right? Someone explicitly coded that in, so what does it mean?

Hi,

Is the system still alive when you see the LED blink?

Yes

Are you able to check gpio (GPIO04 (GPIO3_PI.01).) status in debugfs?

Can you elaborate what you mean by that?

Hi,

GPIO3_PI01 is responsible for this LED and is gpio-65 in sysfs.

sudo -s
cat /sys/kernel/debug/gpio

And then check gpio65

@WayneWWW The gpio output matches the led and I can see it triggering high and low as expected. I read in another thread that the blinking LED denotes over current/undervoltage. I have tried powering the nano from various power sources including a benchtop power supply, and tested both the GPIO power input as well as the power jack. There are no accessories attached to the nano.

Even with all of this, I still see behaviour where the nano boots up for 10-15 seconds before blinking/shutting down. I can see from the benchtop supply as well as from measuring the current that the nano is only drawing ~0.3-0.4A, even though the power supply is capable of 10A.

Do you have further suggestions to troubleshoot? Is my board defective?

Hi,

The board may be defective. Please file a RMA request for it.

I tried to setup a RMA through live chat, but it consistently got stuck at “searching for an available agent”. I have tried reaching live chat on two different instances. When I tried to submit a support ticket with https://nvidia--tst.custhelp.com/, I am unable to login even though I just created the account and definitely have the correct password and username. When I try to reset my password, I never get an email to reset the password. When I try to login through Google, the login through Google button goes to a broken link.

Is there an email I can use to set up the RMA?

Please follow the RMA process:

Hi Kay, as I mentioned in my previous message, I have already tried going through the live chat but never got connected with an agent. Is there an alternative method?

So you can’t enter your contact information to submit the request?
If have the RMA number, then can inform them to pay more attention.