DK 52840 - Hardware failure

[David K.]

Hi all,

I have a DK 10056 rev 1.0.0, and it suddenly stopped working on the Embed side. Using the USB port (the DK one, not the NRF one), the LEDs (4 LEDs for testing purposes) do not light on, but using a battery, it lights on. However the Embed LED (programming led) stays off and the DK is no more detected on my PC.
(I tried different USB cables, I have a second DK and it works).

It happened when I switched off the DK before lunch and could not light it on again.

Any one has an idea ? 

Bests,
David

[Turbo J]

That always happens when you hold the reset button on DK power-up (USB connect).

In order to fix the issue, you must re-flash the interface MCU:

1. Download the "Interface MCU firmware" from the DK's download page (.bin File).
2. Hold reset button and power on DK (by pluggin it into USB)
3. Put the bin file on the newly opened USB drive - Do NOT PUT ANYTHING ELSE THERE!
4. Let the interace MCU flash itself. It should reconnect as J-Link, and is usable again at this point.

Note that you always need to re-flash once the interface MCU was powered with reset down. And, I repeat, do not try flashing other firmware - it may brick the interace MCU.

[David K.]

Hi,

Thanks for the quick answer. 

Powering the DK while holding the reset does not lead to having the usb drive appearing (unlike the operationnal devkit that does have it).

Any idea ?

Bests,

D.

[Jørgen Holmefjord]

It sounds strange that it works with the coin-cell battery but not with the J-Link USB.

Are all the switches in default positions, and no traces/solder-bridges cut?

Have you tested with any of the other power sources (external supply/Li-Po, nRF_USB)?

Did you test it on another PC?

[David K.]

Hi. Yes, that's strange.

So the tests were the followings: 

- USB (DK) : no green led on the MCU, no 4 leds (testing leds)

- Battery coin : no green led on the MCU, 4 leds

- USB and coin together : hieratic blinks on the MCU, no 4 leds

- USB_nrF : 4 leds (no led on MCU, but normal :-))

- No LiPo 

All switches identical to a same second board I obtained temporarily.

So stuck with no JLink interface. And cannot set a usb bootloader on the Nrf,neither.

So sad :-(.

Any additional ideas ?

David

[Jørgen Holmefjord]

It sounds like there is something wrong with either the J-Link OB chip or the power source from the IF MCU USB port. I think you will have to replace the board.

[David K.]

Thanks for your support !