On Wed, Oct 17, 2018 at 5:48 AM Jaroslav Sykora <[email protected]> wrote:
> Hello, > > We have a problem with a destroyed notebook USB port when it was connected > to BeagleBone Black. > Our system: we designed an extension board connected to the BBB > pin-headers P8 and P9. Let's call this the 'ERTEC board'. The ERTEC board > supplies power to BBB via the connector P9, pins 5, 6, which is VDD_5V. The > VDD_5V rail in BBB is basically the barrel jack input. The picture below > shows the setup: > > [image: smoke_from_notebook_usb.png] > *Normally the system works fine. * > > But now one colleague reported this problem: > 1. He had the Mini-USB of BBB connected to a PC (which is grounded...), > and the whole system was powered from a +24V isolated supply and running. > 2. While the system was running, he pulled the USB cable from the PC and > connected it to a USB3.0 port of a notebook. > 3. The USB connector of laptop started smoking. The laptop and BBB didn’t > work after that. > > Any idea why this could happen? So far it seems like an one-off event, but > one could never know :-/ > "smells" like the laptop was grounded.. Either thru it's powersupply, "ethernet" cable, or something else.. Or even thru the user "holding" it... Regards, -- Robert Nelson https://rcn-ee.com/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAOCHtYgkbOSNBoEJ8Nh%3DhMq-P8_eEE-22PUuJW4XnvYgPP_nSw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
