Recover the nRF51 when nrjprog and nRFGo Studio couldn't

You may have a nRF51 chip that is "bricked" and both nRFGo Studio and nrfjprog recover option doesn't work. You can try to use J-link Commander to recover. In some case, J-link Commander showed that it can recover the chip when nrfjprog and nRFGo Studio couldn't.

Jlink Commander should be installed automatically when you install Jlink driver. Here is the screen when you start J-Link Commander and select the J-link programmer (if you have more than one):

When you have the command line ready you can type:

r

w4 4001e504 2

w4 4001e50c 1

w4 4001e514 1

qc

This sequence of instructions can be explained as follow:

r //reset

w4 4001e504 2 //Write to NVMC CONFIG register: 0x02 to enable Erase

w4 4001e50c 1 // Erase all

w4 4001e514 1 // Erase UICR

qc // quit and close