nRF52832 cannot be recovered. Device error: Setting the debug port SELECT register failed while powering up sys and debug regions (Unknown Error in J-Link DLL (error code =-1))

[Shey]

Hello,

i have a custom board with a nRF52832 on it.
TL:DR: i can't seem to get a connection to the chip via the SWD

When i try to recover the device it tells me the debug port is unavailable.

The chip is battery powered and i measured all power lines and the clock so the chip gets 3.3V and 2V on I2C_SCl which should mean the chip itself is running fine.
i am using a J-Link which can measure the voltage of the Vtref which is 3.435V so the port has power aswell but i still can't seem to get a connection to the chip.

Before using nrfutil i used nrfjprog which turned out to be deprecated as i read in the forum. So what happened?

I worked with the chip and it was powered through the battery constantly. It was also connected to the J-Link and i left it there for an hour and came back just to find out that it suddenly won't communicate anymore. The code on it was still running fine but i cannot recover the chip. I read through the forum a lot but i can't seem to find any solution so any help would be greatly appreciated!

[Menon]

Hello,

Could this be a hardware issue, perhaps a soldering problem on the custom board?
From the logs, it looks like the connection is not reaching the chip.

Kind regards,
Abhijith

[Vic0]

I am facing the same issue. And no, it is not a hardware problem. Can you please help out?

[snoopy20]

It's always hardware, so keep tracing your wiring and microscope your chip pins.

[Vic0]

Hey Snoopy, I had the PCBA done by a fab, and I also had them run several electrical continuity tests to verify the connections and traces.

I’m puzzled about why this would be a hardware problem. I also probed several points myself with a multimeter, and everything seems okay.

The only thing I can think of is that the LDO on my custom board outputs 3.3 V, whereas the DK uses 3.0 V. But I don’t understand why that would be an issue, since both voltages should still be within the same logic-level range. 

Thanks.

Vic