# \`trace\` doesn't work over USB for v6.2.2

**URL:** <https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086>\
**Category:** Troubleshooting\
**Created:** [April 23, 2024, 8:56am UTC](https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086 "2024-04-23T08:56:35Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![gauteh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/gauteh/32/269_2.png) [@gauteh](https://discuss.blues.com/u/gauteh)\
**Post date:** [April 23, 2024, 8:56am UTC](https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086/1 "2024-04-23T08:56:36Z")

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Hi,

I just upgraded a notecard to 6.2.2, and I can no longer get any response over USB (ttyACM0). I am connecting using: picocom -b 115200 /dev/ttyACM0

Regards, Gaute

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**Author:** ![gauteh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/gauteh/32/269_2.png) [@gauteh](https://discuss.blues.com/u/gauteh)\
**Post date:** [April 23, 2024, 9:09am UTC](https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086/2 "2024-04-23T09:09:40Z")

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Doesn’t work with 9600 baud rate either.

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**Author:** ![RobLauer](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/roblauer/32/1567_2.png) [@RobLauer](https://discuss.blues.com/u/RobLauer)\
**Post date:** [April 23, 2024, 1:52pm UTC](https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086/3 "2024-04-23T13:52:26Z")

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Hi @gauteh,

I’m going to guess that you’ve tried these common troubleshooting tasks, but this is where I would start:

1. Does the device power on (do you see a flashing LED when plugged in)?
2. Have you tried a different USB cable? Different computer maybe?
3. How did you perform the firmware update? And which Notecard are you using?

Thanks,  
Rob

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**Author:** ![gauteh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/gauteh/32/269_2.png) [@gauteh](https://discuss.blues.com/u/gauteh)\
**Post date:** [April 23, 2024, 2:11pm UTC](https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086/4 "2024-04-23T14:11:37Z")

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The device is working, connected with i2c to an mcu and has contact and functions as it should. firmware update first over the air, and then also tested using stm32programmer. the usb cable is tested with notecards/carriers hundreds of times.

Thanks, Gaute

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**Author:** ![gauteh](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/gauteh/32/269_2.png) [@gauteh](https://discuss.blues.com/u/gauteh)\
**Post date:** [April 24, 2024, 7:04am UTC](https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086/5 "2024-04-24T07:04:26Z")

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Downgrading the firmware to 6.1.1 makes trace work again.

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**Author:** ![RobLauer](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/roblauer/32/1567_2.png) [@RobLauer](https://discuss.blues.com/u/RobLauer)\
**Post date:** [April 25, 2024, 1:52pm UTC](https://discuss.blues.com/t/trace-doesnt-work-over-usb-for-v6-2-2/2086/6 "2024-04-25T13:52:39Z")

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Hi @gauteh,

This is very curious. I wonder if there was an issue with the 6.2.2 upgrade process that led to that error state. If you’re willing, I’d be curious if trying the 6.2.2 upgrade again ends up resolving the issue.

Rob