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Dead-ish nRF52-DK anything else I can try?

One of my nRF52-DK started to act oddly - very brief message in red type flashed up by nRFgoStudio on programming a few times - unfortunately too fast for me to read.

Now Windows 10 cannot connect to that nRF52-DK at all. (but with Ubuntu it shows with lsusb - erratically)

  1. I've tried reflashing the bootloader on the nRF52-DK - goes into bootloader fine, reflashes fine - but still cannot connect to it outside of bootloader mode.

  2. Ive tried this nRF52-DK on another machine - exactly the same behaviour. I've tried other nRF52-DK in both machines - and they behave normally.

Anything else I can try before consigning this board to the rubbish?

  • Hi Martin - and thanks for the very quick reply!

    From your checklist:

    1. My faulty nRF52-DK does not show in Device Manager (and another known good DK does).

    2. Swapped USB leads between the faulty and known good device - no change.

    3. Same behaviour as in 1 and 2 above, on another computer.

    4. The faulty DK does show up as BOOTLOADER and I can reprogram the bootloader firmware.

    5. Supply voltage measures 2.79V on both faulty and known-good DK's (I don't have access to a calibrated voltmeter).

    6. nrfjprog reports JLinkARM version 6.20b

    7. JLink Commander cannot see the faulty DK, but can see the known-good DK.

    One final thing - I've noticed the faulty DK is V0.90 2015.41 - so I presume a fairly early one, is this of any significance?

    (I've several DK's - I'm pretty sure this one was given to me at Nordic Tech Tour. I have another V0.90 DK that works correctly though)

  • Further info:

    I've had the board momentarily connect -> disappear when trying to reflash -> reconnect after the reflash has failed (was able to repeat the sequence twice).

    This board had SB9 cut for current measurement, so I suspected a slight voltage drop (across the P22 link) might be the issue. I tried a brand new (Renata) battery. Also tried resoldering SB9 - neither fixed the issue. I also tried an external 3.3V power supply. Even with an external power supply, the measured voltage on the DK was stil 2.79V

    Is it worth bridging out the protection diodes?

    I'm still suspecting marginal voltage may be the issue - particularly as I've seen the DK momentarily connect - but disappear when attempting to reflash (which is presumably asscoaited with the heaviest current demand).

  • Are you using any kind USB hub? I've experienced some issues with J-link and USB hubs, and I recommend connecting the DK directly to the computer's USB ports if you are having these kind of issues.

    The V0.90 version of the nRF-52832 DK uses a Engineering B version of the nRF52832 IC , and we do not recommend any development being done on engineering samples. So if you have any newer versions(1.1.x) of the DK, I would recommend to use those instead.

  • I've tested with and without a USB hub.

    Oh well, if V0.9.0 is end-of-life, so be it. It's done a lot for a free sample!

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