PPK2 bricked?

[Sebi]

I just got a PPK2.
I was able to use it perfectly with Power Profiler. Great tool!
Today I wanted to learn more about nRF Connect other applications.
(Actually I was looking for a software that could replace iOS nRF Connect to perform DFU upgrades from my PC).

So I launched the Bluetooth Low Energy software, the first in the software list.
I wanted to start a scan but the icon was grayed (at first I thought the scan would rely on my PC bluetooth adapter).
I noticed I could select the PPK2 in the device list so I selected it (it is indeed made with a nRF53840).
The Bluetooth Low Energy software asked me if I wanted to flash my PPK2.
The flash process started.

After a few seconds, I got an error message in the log and the PPK2 LED stopped flashing.
I tried to launch Power Profiler again but the PPK2 had disappeared from the device list (there was no device shown anymore).

I rebooted. I retried.
Under Windows Device Manager the only difference when plugging the PPK2 is that "USB Root Hub (USB3.0)" appears in the list.
The PPK2 LED is still off.

Can you help me fix my PPK2 not working anymore?

[Sebi]

Dear Stian, my problems with the PPK2 are not over...

I didn't do anything more in the meantime I thought it was fixed.
But this morning when I wanted to do some measurements I plugged my PPK2 in my computer but it is not recognized anymore.

I tried under Windows and Mac OS X, in every one of the 4 USB C ports, using 2 different USB C to USB 2 adapters, using 2 different USB cables...

The LED is flashing green in a slow dimming pattern when I plug the PPK2 (meaning the power app firmware is running correctly?) or turns on red if I set the PPK2 in DFU mode.

My computer sees the the USB C to USB 2 adapter when I plug it in, but no PPK2 afterwards when  I plug it in using the adapter. The PPK2 LED starts flashing though. If I connect a different USB device (e.g. a bluetooth adapter) instead, this other device is been discovered though.

Thus I believe my PPK2 has a hardware failure that makes it not reachable now and then.

Can you help?

[Stian Røed Hafskjold]

Hello. Did you use the correct USB port on the PPK2? There are two different. One of them is only for power.

[Sebi]

Definitely!
I made sure to use the USB port with power & data.
(even while having the board upside down with its cover off to switch the PPK2 in DFU mode. I admit it was confusing...)

[Stian Røed Hafskjold]

Ok sorry, I had to ask :)

Not really sure what is wrong. If the LED is flashing green slowly, it means that the firmware is running successfully on the PPK2. Could it be some driver issues on the computer? Are you able to test using another computer? I've also seen random issues before with bad USB cables. Not sure if you have tried more than one cable, but if you have another one it's worth trying.

[Sebi]

I tried with 2 different USB cables (that work correctly when connected to an external HD).

I tried yesterday on my MacBook Pro
...on all its 4 ports, on Windows 10 (under Bootcamp) and on Mac OS X.

I have just tried on a cheap HP laptop running linux (equipped with USB 2 ports).
The PPK2 is still not being detected...

What I don't understand is that I was able to reflash the firmware. But the day after, without doing anything, it stopped being recognized. It is like the PPK2 is powered but the hardware for serial communication got damaged in the meantime.

[Sebi]

I borrowed another PPK2 this morning and it worked properly on my computer.

I just tested my PPK2 again (same computer, same adapter, same cable, same port) and it is still not recognized; the LED is flashing thought...