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]

Hi Bjørn and Varun, don't want to interfere but we have seen the same issue with our nRF52 DK boards, case created on the official support portal, boards sent to Norway, issue acknowledged (meaning Nordic could see that boards cannot be recovered by any of their tools) and we are still waiting for resolution (my actual fear is that there is HW bug in SWD or other module on nRF52 REV1 which can cause unrecoverable chips under certain conditions caused by FW...) So I'd be careful to call this rare or unusual (we can even reproduce it, unfortunately only with certain FW binaries which we cannot really share). Cheers Jan