nRF52840 does not respose after I flashed hex in nRF Thread Topology Monitor package

[DeanC]

I am trying to use TTM (nRF Thread Topology Monitor package) with a newly bought nRF52840 Dongle (PCA10059) on Windows.

Following the instruction at https://docs.nordicsemi.com/bundle/ug_nrf_ttm/page/UG/nrf_ttm/ttm_adding_topology.html, I flashed the hex (nrf52840_xxaa_mbr_pca10059_usb.hex) inside the TTM package (nrfttmwin32x640130.zip) with Programmer, flashing process was successfully done with no any warning message, but there was no COM port appeared in TTM.

I noticed that the led on the dongle was not lit, so I unpluged and pluged in the dongle but it didn't help, and there was no any new USB device detected in device manager after I plugin the dongle.

I'm able to flash back another hex for nRF Sniffer for 802.15.4 Desktop tool and get the exact same dongle working to sniff thread packet with wireshark. so I'm guessing this is not an hardware issue?

[Sigurd Hellesvik]

Thanks for the clarification.

I was able to make it work with that hex file, so then we know that part is fine.

Could you perhaps borrow a PC from someone else to try the dongle with another PC?

[DeanC]

I've tried it on my pc and my laptop, none of them works.

This makes me think that the one I bought from internet might originally be defect or even a fake one.

I noticed that there is no label sticker on the back of the device that I bought, could this somehow be a fake one?

[Sigurd Hellesvik]

It could be that it is a counterfeit indeed. So this is a very real possibility for the source of the problem.

However, one detail that stands out to me is that you see nothing in the "select" option in the TTM desktop program. On both linux and windows, I see some COM ports listed there, even when no nRF devices are plugged in. These COM ports are likely other USB devices, so it looks like the TTM desktop program.
The fact that you get nothing in this menu could mean that the TTM program does not have proper access to USB ports or something along those lines.

[DeanC]

Thanks for the clarification, I'll try to get another dongle to see if it is a hw defect or a counterfeit one.

As for the COM port access, I don't think this is the case because I do see a COM port appeared if the same dongle is flashed with other hex, e.g. the one in provided in "nRF Sniffer for 802.15.4" git. but there will be no response for the CLI commands as it is not the correct hex to use (I guess).

However, the dongle works perfectly w/ "nRF Sniffer for 802.15.4", I can get thread packets with wireshark.