Issue recovering nRF5340 Audio DK

[kumareshdhotrad]

Hi All,

I have an nRF5340 Audio DK which has problem with the network core. 

When I connect the USB to board or try to recover the board the MCU light at the bottom of the board continuously blinks.

I have tried recovering the board with nrfjprog described below.

nrfjprog --version
nrfjprog version: 10.24.2 external
JLinkARM.dll version: 8.18
PS C:\Work\hci_ipc> nrfjprog --recover --coprocessor CP_NETWORK
[error] [ Client] - Encountered error -105: Command connect_to_emu_with_snr executed for 14865 milliseconds with result -105
ERROR: Unable to connect to a debugger.
[error] [ Worker] - JLinkARM.dll Open returned error 'Cannot connect to J-Link.'
ERROR: The JLinkARM DLL timed out while communicating to the J-Link probe.
ERROR: If the error condition persists, run the same command again with
ERROR: argument -- log, contact Nordic Semiconductor and provide the generated
ERROR: log.log file to them.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed.
PS C:\Work\hci_ipc> nrfjprog --recover
[error] [ Client] - Encountered error -105: Command connect_to_emu_with_snr executed for 14871 milliseconds with result -105
ERROR: Unable to connect to a debugger.
[error] [ Worker] - JLinkARM.dll Open returned error 'Cannot connect to J-Link.'
ERROR: The JLinkARM DLL timed out while communicating to the J-Link probe.
ERROR: If the error condition persists, run the same command again with
ERROR: argument -- log, contact Nordic Semiconductor and provide the generated
ERROR: log.log file to them.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed. 

When I open jLink after the mcu led is in solid state, Jlink says that it is in bootloader. After which it flashes the OB and I get the below logs post which the MCU led starts blinking.

J-Link connection not established yet but required for command.
Connecting to J-Link via USB...Updating firmware: J-Link OB-nRF5340-NordicSemi compiled Nov 7 2022 16:22:01
Replacing firmware: J-Link OB-nRF5340-NordicSemi compiled May 18 2021 BTL
Waiting for new firmware to boot
FAILED: Could not read J-Link capabilities.
bytes, received 0 bytes !
Could not read J-Link capabilities.
Cannot connect to J-Link
J-Link>

Please help recover the board.

[dejans]

Hi,

Have you tried to use nrfutil for recovery?

nrfutil device recover --core Network
nrfutil device recover

Best regards,
Dejan

[kumareshdhotrad]

Hi Dejan,

Apologies for the delayed response. I tired recovering the device a few hours later which worked.

[dejans]

Hi,

Thank you for the update.

Best regards,
Dejan

[SableHarrington]

It seems your nRF5340 recovery issue may relate to corrupted boot memory. Using a reliable EEPROM like M27C512-90C1 can help ensure stable firmware storage during recovery processes. Its consistent read/write performance supports dependable data retrieval, minimizing bootloader errors when flashing the board or restoring the network core through nrfjprog or nrfutil commands.

[kumareshdhotrad]

I have entered this state again. Disconnecting the board for a while and reconnecting did not help. Neither did opening the Jlink commander.

I get these logs:

PS D:\Work\nRF\5340\nrf5340_audio\unicast_server_binaries> nrfutil device list
1050193515
Product J-Link
Board version PCA10121
Traits usb, jlink, seggerUsb, devkit

Supported devices found: 1

PS D:\Work\nRF\5340\nrf5340_audio\unicast_server_binaries> nrfutil device recover --core Network --serial-number 1050193515
 Failed to recover 1050193515, Timed out waiting for response from worker. Error: One or more recover tasks failed:
* 1050193515: Timed out waiting for response from worker. (Generic)

PS D:\Work\nRF\5340\Pendant\nrf5340_audio\unicast_server_binaries>

[kumareshdhotrad]

I’ve identified the root cause. It turned out to be due to multiple J-Links connected simultaneously along with several active VS Code instances. The GDB servers launched by VS Code were interfering with each other and putting the J-Links into an unstable state.

After closing all VS Code instances, the J-Links reset properly and I was able to recover the boards without any issues.