PCA10056 erase error

[mjw]

I'm using a PCA10056 (NRF52840 Preview DK) v0.9.1, and trying to erase the existing firmware, but running into issues.

I've tried nrfjprog -f NRF52 --eraseall with version 9.6.0 of the NRF Tools and version 6.16a of JLink. The log file contains:

• FUNCTION: open_dll.
• FUNCTION: open_dll.
• FUNCTION: enum_emu_snr.
• FUNCTION: enum_emu_snr.
• FUNCTION: enum_emu_snr.
• FUNCTION: enum_emu_snr.
• FUNCTION: connect_to_emu_with_snr.
• FUNCTION: connect_to_emu_with_snr.
• FUNCTION: connect_to_emu_without_snr.
• FUNCTION: enum_emu_snr.
• Device "NRF52832_XXAA" selected.
• FUNCTION: read_device_version.
• FUNCTION: read_device_version.
• JLinkARM.dll CORESIGHT_WriteAPDPReg returned error -1.
• JLinkARM.dll CORESIGHT_WriteAPDPReg returned error -102.
• FUNCTION: close_dll. FUNCTION: close_dll.

When I run nRFgo Studio, I get the following message, and when trying to recover:

My nRFgo Studio is version 1.21.2.10.

I've been able to put the device in bootloader mode, and reload the J-Link OB bootloader image, but this did not make any difference. Another post suggested disabling mass-storage device mode, which I have done through JLink Commander, but still no luck.

Does anyone know what may be wrong with my device?

[endnode]

No, I've just seen too many JTAG/SWD programming errors caused by bad USB cables that I'd bet it causes yours as well;) Is nRF52840 PDK board unchanged, nothing is attached to any port/PIN? Is USB cable short and well shielded? Can you try another USB port and/or machine? You can also check status/version of SEGGER J-Link OB FW by running J-Link Configurator tool from SEGRE J-Link SW package you have installed on your machine. If it doesn't see the board or doesn't recognize the FW then you might have other problems...