NRF5340 AUDIO DK (PCA10121) Headset Issue J-LINK V7.98i Firmware Restoration/ Programmer fail to connect

[LuckyWinner]

Hello everyone,

My problem is that I could not flash one of my NRF5340 Audio DK boards, the program that is installed before was headset configuration right.
I am using SDK 2.6.1 and have also downloaded 2.8.0.
And two hours before the device was directly detected, I am not sure what I have done wrong or how to solve the problem.

What is interesting is that when I switch on the gateway and the correct headset, Bluetooth connects. But the main problem is that I cannot program the device.

Setup:
I have a total of 3x NRF5340 Audio DK (PCA10121 v0.8.2):
1 is configured as gateway (green light)
1 as left (blue light)
1 should be right (light magenta)


Hardware situation:

When I connect the Audio DK to the PC, I only get LED3 blinking (about 500ms off 500ms on) and RGB2 blinking very fast. OBEXT and HUB are also always on. The middle LED is magenta.
AND IFMCU is blinking fast at the beginning and with "nrfjprog -i" I do not get any number.

Pop-Up: J-Link V7.98i (After arround 2 Minutes)
Later, after a pop-up of J-Link V7.98i Firmware Restoration (see picture below), it is also always on.
Then I could use "$ nrfjprog -i" to read the number, but if I start flashing or any of the other things described before, it always gets stuck...
The reset button does nothing.
In the Windows device manager i can see two USB serial ports devices (COM27 and COM28).

If i try to program the Problem Audio DK , it gets stuck at the programming point:
"Programming net core on": xxxxxxxxxxxxx headset left" (x's are the number ID of the back) even after 1 hour of waiting (the others only took a few minutes).

Tried to Recover:
I have tried to reconnect the device to the PC several times and have also run "nrfjprog --recover" but have also got stuck in the recovery process.
And also in this order:

nrfjprog --recover --coprocessor CP_NETWORK

nrfjprog --recover

Tried to Reinstall and Erase:
I have tried this command in various combinations: python buildprog.py -c both -b debug -d both --pristine -p -f
I did tried to erase it via programmer and via "$ nrfjprog --eraseall --qspieraseall --log" (and other combinations of eraseall)
Also i did tried to erase and flash via "VS-Code". Tried to update the segger J-link and use another SDK Verision (2.8.0).
Also restarted my pc and all programms. but still noting worked.


Via the Programmer Tool of the nRF Connect for Desktop i have this Screen and the Log below:

23:54:14.959

Selecting device with the serial number 000960337540

23:54:23.672

Error: Failed with exit code 1. Failed to device info one or more devices: * 960337540: [Probe] Timed out waiting for response from worker., code: Generic. Message: Operation device-info failed, [Probe] Timed out waiting for response from worker.

23:54:23.673

Auto-reconnecting to device with the serial number: 000960337540

23:54:23.673

Selecting device with the serial number 000960337540

23:54:23.804

Error: Aborted ongoing nrfutil ["device","device-info","--serial-number","000960337540","--json","--log-output=stdout","--log-level","off"]

23:54:29.142

Error: Failed with exit code 1. No devices with requested serial number(s) or trait(s) found.

23:54:29.142

Selected device with the serial number 000960337540

23:54:29.143

Using nrfutil device to communicate with target via JLink

23:54:29.530

Error: Failed with exit code 1. No devices with requested serial number(s) or trait(s) found.

23:54:29.530

Error: Failed with exit code 1. No devices with requested serial number(s) or trait(s) found.

IF i click Erase all this gets added to the log:

00:09:02.208

Error: Failed with exit code 1. No devices with requested serial number(s) or trait(s) found.

00:09:02.693

Error: Failed with exit code 1. No devices with requested serial number(s) or trait(s) found.

For Reset it is doing the same:

00:09:43.102

Error: Failed with exit code 1. No devices with requested serial number(s) or trait(s) found.

00:09:43.487

Error: Failed with exit code 1. No devices with requested serial number(s) or trait(s) found.

[LuckyWinner]

After a lot of try and error i solved the problem by this thread of a Segger Forum:
forum.segger.com/.../

The suggested steps from the forum are:
- Power cycle the J-Link.
- Open J-Link Commander from the V7.52a release
- Accept the FW update

__________________________________

FOR THE PROBLEM SOLVING I USED THESE:
1. Power cycle the J-Link.

2. Open J-Link Commander from the V7.52a release ---> I used 7.98i and 8.12c but mainly 7.98i


I added this step:
3. Use ? for seeing all able functions then use "USB [<SN>]" --> for [<...>] use the ID/Serialnumber on the back of the Audio DK Kit (For detail explaination see below)
If you can not find the Number, it is also possible find the number via Device Manager and the properties window of the COM Port or J-Link.

4. Accept the FW update --> did tried many times and "cross out" automatic close Checkbox!

5. After that the Audio DK is recognised in the J-Link Commander and its able to see the all the details.

6. Next step is to launch via Toolchain Manager a "Open Bash" and navigate to ".../ncs/v2.8.0/nrf/applications/nrf5340_audio/tools/buildprog "
use there "nrfjprog --recover --coprocessor CP_NETWORK" and wait till its recovering (could take up to 30sec but i did wait 60sec for safety)

7. Then i changed the "nrf5340_audio_dk_devices.json" and replaced the number 1000 according to the SN of the Audio DK (do not forget to save the file!!)
8. run the "python buildprog.py -c both -b debug -d both --pristine -p -f"

9. If there is again a error/fail on one of the two cores of the nrf5340, i did retried the steps 6. to 8.


___________________________________

J-Link Commander Problems could occure:



After a few seconds "the problem": 



The use "?" to see all options:

And choose USB [<SN>] (write it in the next line and press enter)