nRF52840 Dongle Bricked After Programming

Question

Hi, 
 I have a nRF52840 Dongle connected up to an external j-link debugger. I have been using this over the past few weeks with no issues and unfortunately I have managed to brick it. 
 When I try to connect, i get an error saying that no board is connected. I have tried nrfproj from a comment line, the j-link lite tool and the nRFconnect programmer, all complain that they can not see the dongle. 
 (Actually, I had managed to do this on two separate dongles, on one the green LED remains permanently lit and on the other, there are no leds lit) 
 This issue seems to be similar to what Im seeing 
 https://devzone.nordicsemi.com/f/nordic-q-a/39596/the-nrf52840-dongle-can-no-longer-be-accessed-after-flashing-hex-file/153553#153553 
 Here the answers was to use the reset button. I have tried pushing, holding. tapping the reset with no changes. 
 How can I bring the boards back to life? 
 Thanks, 
 Rod

Jared · Accepted Answer

Ok, this would explain the behavior that you're observing. The chip is kept in reset state due to the reset pin being pulled low. Could you try shorting R2 which would result in the reset pin being pulled up to VDD? And then run a recover command with a debugger that supports 1.8 V. Just make sure that the reset pin isn't pulled down by something externally first.

RodWatt · Answer

Hey Jared, 
 Yes!! That worked, thanks. I am now able to program the dongle again. Any thoughts on how I could have got in that state? Just so I can avoid next time. 
 Rod

nRF52840 Dongle Bricked After Programming

Top Replies