I’ve been using a 4 port USB hub through the USB OTG port for several months now. Tonight I powered my TK1 with a 3S Lipo battery for the first time and it worked fine (the battery was giving 11.3V). I then shut the system down and disconnected the battery to give it a full charge (12.3V). When I hooked the battery up again, the barrel connector on the TK1 arced as I connected it. This seems to have damaged the USB OTG port because it no longer provides any power. The rest of the board seems to be fine, including the USB3 port. Is there any hope of repairing this port? I hate to think I can no longer flash my TK1. Thanks for your help.
When in device mode the port should not provide power, though many devices do consume power in device mode (Jetsons have their own power so they do neither consume nor provide power in device mode). To flash you use recovery mode, and recovery mode implies device mode on the port.
I suggest you put the Jetson in recovery mode and see if the provided micro-B USB cable allows the host to see the Jetson (don’t use the wrong cable type, then the Jetson would never be visible as a device). The host should have output from this:
lsusb -d 0955:7140
Hello linuxdev. I apologize for the delay in following up on your suggestion. I have successfully flashed my TK1 many times previously. Now when I put it into recovery mode, then use lsusb on my host machine, the TK1 does not show up.
Just to clarify what I said initially: I had a USB hub connected to the OTG port. The hub had no source of power except from the USB connection. I had 4 low power devices connected to the hub: wireless keyboard and mouse dongle, wireless xbox 360 controller dongle, Arduino Mega 2560 and lastly a small wifi access point. All of these devices were being powered through the hub and they functioned properly. Since the battery power incident I described above, no device connected to the OTG port works. The hub was also damaged in this event.
I didn’t have any device connected to the USB3 port during the power incident. I can connect a new USB hub to this port and all devices function properly. Unless the OTG port can be repaired, it seems I can no longer flash it.
One of the problems of miniaturizing connectors is a shrinking trace size and smaller physical protection. I would not be surprised if there were conditions which broke a trace or damaged the connector. I doubt it would help in this case, but some people have been known to put epoxy over the body of the micro-USB connectors to the circuit board as a way of reducing strain from the cable being constantly inserted or removed. If the OTG port is not useful in device mode you are correct that the Jetson won’t have the ability to be flashed. There are some tricks available to update such a system’s root partition through something like SD card, but this is definitely not convenient.
It should be of interest though that there is some dynamic routing of traces to that connector which changes depending on whether it is in recovery mode or host mode. Even if the port cannot provide USB bus power…useful only in host mode…it may still work in device mode. The fact that you cannot see the device in recovery mode from your host kind of seals the fate though, and implies it isn’t just bus power which is missing. You might want to look very closely at traces and the connector itself to see if maybe you can spot some tiny break in the traces (a lot of skill and luck could repair such a defect). If the problem were destruction of some component within the TK1 SoC itself I suspect it is more likely you’d have had complete failure. As such I’m tempted to believe that whatever failed is on the surrounding board rather than the SoC. Possibly at the moment of arcing a trace burned; the issue could be a power delivery function, but if that were true, then most likely the Jetson would not work at all.