Issues with the USB-C Port (5B) on the Jetson Thor Developer Kit

[waylo]

Hello, recently we tested nearly 20 Jetson Thor Developer Kits and observed the following different phenomena:
Phenomenon 1: For 10 of the devices, right out of the box, without an OS installed and powered on only, we connected a USB hub (with an LED) to the USB-C port (5B). The LED lit up normally, indicating the port was supplying power correctly. For the other 10 devices, connecting the USB hub did not light up the LED, meaning the port was not outputting power.

Phenomenon 2: Among the 10 devices that did not supply power from the USB-C port (5B) without an OS installed, after installing Jetpack 7.2, 9 of them started supplying power normally from the USB-C port (5B) after the first boot into the system and plugging/unplugging the connector 1 to 2 times. After that, it supplied power normally regardless of subsequent plugging and unplugging. Subsequently, if the device was powered off and turned back on within one minute, the USB-C port continued to supply power normally. However, if powered off for more than 3 minutes, the port stopped supplying power and required 1 to 2 plug/unplug cycles to resume power output. When powering normally, connecting a USB flash drive via a USB-C to USB-A cable allowed the drive to be recognized properly.

Phenomenon 3: For the remaining 1 device from Phenomenon 2, the port failed to supply power under any circumstances. However, when this USB-C port (5B) was used as the power input connected to a USB-C power adapter, the USB-C port (5A) worked normally.

Jetpack Version: Jetpack 7.2 (R39.2.0)
Power Supply: Using the included USB-C power adapter from the box, connected to the USB-C port (5A) for power.
Test Tools: A USB-C to USB-A hub (with an LED) and a USB-C to USB-A cable connected to a USB flash drive.

Regarding the above phenomena, are there any solutions?

Supplement:
Installation Diagram

1、USB hub with LED indicators

2、Normal Condition

3、Abnormal Condition（Indicator LED is off）

4、USB-C to USB-A cable connected to a USB flash drive.

[juanignava]

Hello @waylo !

Based on NVIDIA’s documentation, the USB-C port 5B/J82 is expected to support USB host/device mode. NVIDIA also has a forum thread where their support team mentions that if J82 does not output VBUS with the default JetPack image, it may indicate a hardware issue.

Reference:
https://forums.developer.nvidia.com/t/thor-dev-kit-usb-c-j82-not-working/370984

For the units that started working after installing JetPack and reconnecting the USB device, this may be related to USB-C role. I would recommend testing with the default JetPack image, powering the board through 5A/J81, using 5B/J82 as the USB host port, and collecting dmesg, lsusb, and VBUS measurements before and after reconnecting the device.

For the unit where 5B/J82 never provides power, it would be reasonable to treat it as a possible hardware issue and escalate it to NVIDIA for confirmation.

Juan Navarro
Embedded SW Engineer at RidgeRun
Contact us: support@ridgerun.com
Developers wiki: https://developer.ridgerun.com
Website: www.ridgerun.com

[waylo]

@juanignava

RidgeRun

Thank you for your suggestions.
For the development kits that require the OS to be installed first and need the USB device to be unplugged and replugged to be powered and recognized, the flashed image is exactly the default NVIDIA image.
As for the development kits that fail to be powered and recognized under any circumstances, I will proceed with the RMA process.

[WayneWWW]

We are checking this internally.

Also want to confirm. Will you see different behaviors when using rel-38 instead of jp7.2?

[waylo]

I haven’t tried installing rel-38 yet. Because I tested on several brand-new, just-unpacked devices with no system installed, and found that on some devices the 5B port can supply power while on others it cannot, so I don’t think it has much to do with the system version.

[WayneWWW]

@waylo

Because I tested on several brand-new, just-unpacked devices with no system installed,

I still don’t get what does that mean " just-unpacked devices with no system installed". Thor does not have internal storage so you must install system on NVMe. or other SSD

What is the point to test on such setup here?
Checking USB function under such setup seems quite pointless. We expect that every new unpacked device should have your manual installation there.

[waylo]

It doesn’t really make much sense to test the USB without installing a system — it’s just that we happened to observe different behavior across different devices, so we’re concerned about potential hardware variations.

I’ll find some time later to test whether the same phenomenon occurs with version 38.2.

Regarding this issue, have you been able to reproduce the same behavior on the devices you have on hand?

[WayneWWW]

Actually there are still some known USB issue there that is not resolved. However, that is just software issue but not hardware problem.

That was why release version could matter here. BTW, please test rel-38.4. No need to test rel-38.2 anymore.

[waylo]

After flashing 38.4, the same abnormal phenomenon still occurs.

[SamM11]

Hi @waylo ,

How did you update the PD firmware on the Thor DevKit? Could you share the steps you followed?

Thanks!!

[Jerry-W]

Hi WayneWWW，

I am experiencing the same issue.

I am powering the Jetson AGX Thor Developer Kit using the original power adapter connected to J81. After the system boots, USB devices (such as a USB drive or mouse) connected to J82 via a USB-C to USB-A cable are not recognized.

Additionally, when the AGX Thor Developer Kit is powered on, I connected it to my host PC using a USB data cable, but lsusb on the host does not detect the Thor kit at all.

I have tested both Jetson Linux BSP R39.2 and R38.4, and the behavior is identical.

Could you please advise whether this is a software issue or a hardware problem with my AGX Thor Developer Kit?
If it is a hardware defect, I would like to proceed with an RMA request.

Thank you!