NRF51 DK (nrf51422) Bricked? Cannot Recover?

[byron l]

Hello, I am now having problems to get NRF51 DK to work. My computer is connected to board with USB. It can recognize it.

Now, here is what is something strange, when I go to nrfgo studio, it says that it cannot detect the device.

I clicked the recover button, but then it turned out that it failed because the log says "Unable to find or open the JlinkARM.dll. I tried uninstall all nordics and seggers and Keil 5.17 (including registries and manual delete them). Reinstall all of them. It still gives an error on JlinkARM.dll. I am able to boot to bootloader. I tried reflashing J-Link OB-SAM3U128-V2-NordicSemi 150828.bin while in bootloader mode, but nrfgo studio still cannot recognize it.

In Keil, when I upload a project to the board, it goes an error about reset pin 15 is high, it should be low. But I haven't cut any components out.

I am now running out of solutions. Can anyone help me solve this issue? I appreciate it.

Thanks

Update, I tried to use nrfjprog --recover, and --verify, it still cannot recognize my NRF51-dk.

[monpetit]

Can you detect an external target through your nRF51 DK? It might be worth a try. You should figure out what is out of order, whether J-Link or nRF51422.

[monpetit]

Then you can check the condition of nRF51422 on your nRF51 DK with other debugger.

[byron l]

Thanks for your reply. I checked the voltage of the nrf chip. It suppiles 0.84 volts when powered with usb cable. I probed between the nrf current measurement and ground. So I guess the chip is burned out then.

[Hung Bui]

Hi Byron,

You can try to check if it's the issue with the power supply's voltage regulator or it's the nRF51 chip damaged by cutting solder bridge SB9. Then the power supply to the chip will have to go through P22.

[byron8899]

Hi Hung, sorry for late reply. Yes, I found out the chip is dead. Thanks and happy holidays