JLink not recognized after setting --rbp ALL

[VarunR]

I'm using the nRF52 Dev board and set the --rbp ALL option while using nrfjprog. It worked fine, and I am able to do OTA updates as I was testing the bootloader example. But the jlink is no longer recognized. I cannot undo the readback protection as I can no longer recognize the jlink on the board. I get the following error in keil: ***JLink Error: Communication timed out: Requested 20 bytes, received 0 bytes ! Could not transfer JTAG data. DAP error while reading DP-Ctrl-Stat register. Error: Flash Download failed - Target DLL has been cancelled

And I can't use any of the methods given here to disable the RBP: devzone.nordicsemi.com/.../

Has anyone seen this problem before? Any help would be appreciated, thanks!

[endnode]

Well then you hopefully get some attention of Nordic's support at your question. In my case submitting it through "My Page" support zone on main Nordic web site helped, if you can share the source code and you can develop reliable procedure how to reproduce then even better. Upgrading to NRFTOOLS v9.0.0 worked for all our locked boards and we don't have any problem since then (some of our engineers reported on older versions of the toolchain that board which was unrecoverable for some time started "magically" work after they kept it unpowered over night or longer, but there were no exact evidence that this shows some real issue so we never investigated these strange occasions).

Cheers Jan

[abe]

Dear all, I have same issue with my NRF52 Dk board. I'm not able to debug, and i have no way to connect it. I used jFlash and NRFTOOL v9.0.0, but board will disconnect. When I try to connect the board, the green led near usb connector (debug led I think...) will ligths off and after few seconds ligths on. Jflash and NRFTOOLS answer "could not connect the target" Kind regards, Abele