Failed to Connect Target

[Sahil Anchal]

I procurred two NRF52DK boards and in both the boards I am facing the similar issue of "Failed to Connect the Target".  When I am running the nrfutil device recover command, it showing follwing error:
x Failed to recover 1050389761, Emulator error: Failed to open connection
Error: One or more recover tasks failed:
* 1050389761: Emulator error: Failed to open connection (Generic)

also when running nrfjprog --recover -f nrf52 command
it is shwoing the following error:
"Recovering device. This operation might take 30s.
[error] [ Worker] - Encountered error while performing post-recover cleanup. -90: Access protection is enabled, can't read device version.
[error] [ Client] - Encountered error -21: Command recover executed for 30178 milliseconds with result -21
ERROR: Recover failed. Please make sure that the correct device family is given
ERROR: and try again."


I am not able to use these boards at all and sort of struck at this and have been wasting my time for the last one week trying every bit of commands provided to recover the device but have no success at all so far.

[dejans]

Hi,

Which versions of the tools (nrfjprog, nrfutil, nrfutil device) do you use?

Best regards,
Dejan

[Sahil Anchal]

Hi,
I am using the folliwng versions:
nrfutil --version: nrfutil 8.0.0 (54d8087 2025-01-07)
nrfutil device --version: nrfutil-device 2.11.0 (5778cc4 2025-05-15)

nrfjprog --version: 10.24.2 external
JLinkARM.dll version 7.66b

Regards

[Sahil Anchal]

Hi,
Does this mean that both dev kits are now beyond repair?
To understand better: is it possible that AP protection was enabled accidentally through example code or SDK usage?
If so, how can I prevent this in the future?

Regards

[dejans]

Hi,

Sahil Anchal said:

To understand better: is it possible that AP protection was enabled accidentally through example code or SDK usage?

Enabled AP protection should not be the issue here. "Erase all" removes AP and (in case of nrf52832) "erase all" should always be possible. The only way that could prevent "erase all" from working is shown in previously mentioned errata.

Could you describe and/or show in more detail what you had done before this problem happened?

Best regards,
Dejan

[Sahil Anchal]

Hi,

I was just running example code(twi_sensor_pca10040) using Segger Embedded Studio, it was getting flashed on the device succesfully for few times, but all of sudden it started throwing error "Failed to Connect to Target".

[dejans]

Hi,

Before starting with the process shown below, you should download the newest version of nrfjprog
https://www.nordicsemi.com/Products/Development-tools/nRF-Command-Line-Tools/Download

1. First, you need to ensure that you can run the debugger while power cycling the nRF, which is done by cutting SB9:

docs.nordicsemi.com/.../prepare_board.html

This allows for current consumption measurement on the "nRF Current measurement" header. Connect a jumper wire or similar to this header.

2. Try running  nrfjprog recover loop batch script. Create a file, name it nrfjprog_recover_loop.bat or something like that and copy these lines into it.

:loop
nrfjprog --recover -f nrf52
goto loop

Then run the script.

3. While the script is running, you power on/off the nRF by removing the jumper-connection on "nRF Current measurement" header.

Could you try this and report back if you run into any issues?

Best regards,
Dejan

[Sahil Anchal]

Hi,

I have implemented the procedure as per the instructions, the device was still not recovered.
I have attched the log file.

Thanksnrfjprog_recover_loop_log.log

[dejans]

Hi,

Sahil Anchal said:

I was just running example code(twi_sensor_pca10040) using Segger Embedded Studio, it was getting flashed on the device succesfully for few times, but all of sudden it started throwing error "Failed to Connect to Target".

Did both nrf52-DKs get into the same problem after flashing the same example code in Segger Embedded Studio? Are there any differences in the actions you took on both boards before observing the error?

Best regards,
Dejan

[Sahil Anchal]

Yes, in my nrf52-DK (1050389761), I was able to run the blinky code few times, and then I try to run the twi_sensor_pca10040 example code after the first successfull flash, it started showing the "Failed to Connect to Target" error in every flash attempts.
Then i thought to try it with the another nrf52-DK(1050379504), the same  twi_sensor_pca10040 example code, it flashed successfully first time and when I try to flash it again it started showing the same error.
After this, I could not use both nrf52DKs.

Thanks