We have recently deployed 50 units of Rock3A for IOT purposes, with 4 USB ports fully utilized. The board is powered from the 40pin header, using 5V 2.5A, via a add-on board containing the 5V PSU plugged on the 40 pin directly.
One port for touch screen, one for USB speaker, one for USB-serial and one for 4G modem (separately powered).
We have observed some of the units (around 5 of them) have issues with one of the port disconnecting after several hours, and the port appear dead. To revive the port, a reboot is needed.
What is the possible reasons behind this? Manufacturing defect? These units have dates of Jan 2022, Aug 2022 and Nov 2022 as far as I can tell from the barcode on the boxes, and some come in paper box without the plastic boxes, though we are not sure faulty ones are which date codes.
Is there something we can do to reset the port without rebooting?
Thanks.
USB unstable, sometimes disconnect by itself and need reboot to fix
Hi. I’m not an expert but would begin by:
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Checking the version of the boards to verify if all of them correspond to the same batch. The MAC address is indicative of similar date of productions.
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When the issue occurs, use ‘dmesg’ command to check what does the kernel has to say.
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Try with a higher current PSU. USB modems can pull high current at certain times.
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Try using the problematic boards without one of the USB devices connected at a time, and check if there is common determinator in the port crash.
USB is just not great connector, have You tried just to change cables between units? Insert them firmly?
Where they are running? Any chance for vibrations?