NRF52840 dongle - not working after short circuit

[LRA_]

Hello everyone,

We're using a NRF52840 dongle for a Uni project.

We got a couple of dongles it.
I stupidly used a image on google to know the pinout because it's hard for me to see the pin numbers in the board. Lucky me - it was completely wrong. So I shorted VDD out with GND...
The board now doesn't turn on from USB though it can be powered externally.

Even more weird, if I power the 3.3V for a second it will start working from usb power only.
Is there any way to solve this or do I have to use external regulator from now on?

[hmolesworth]

Try replacing FB1 and FB2 with 0R resistors; in practice that means just short both FB1 and FB2, either by soldering or holding something metallic.Note I don't mean connect them together, you just want to bypass the filter which can fail if you pull significant current or even sneeze on them. They act like fuses.

[LRA_]

that what I was thinking. I tried to measure somehow if that was the problem but didn't find anything evident to I let it be.
The VBus pin and GND pins are okay (not sure if they are after the beads) so I just cut and soldered the sb1 and sb2 and added an external regulator.

So there's no trying now :/ 

Thanks for the input, if I decided to undo what I did and try that I will report back.

[joric]

I have a problem with nRF52840 (e73 module) that shows VCC shorted to GND permanently. Anyone knows how to fix that? It might be firmware/registers because it was in high voltage mode set to 3.3V. Related issue: devzone.nordicsemi.com/.../nrf51822-showing-short-in-power-after-it-is-first-powered-on-a-custom-board

[Simonr]

Hi

This ticket is almost 2 years old now. I suggest that you create a Private ticket of your own, where you describe your problem in detail and upload schematics and layout files so we can do a HW review for you, and find out what is wrong.

Best regards,

Simon