DK 52840 - Hardware failure

RE: DK 52840 - Hardware failure

testsweng — Thu, 23 Jul 2020 14:18:47 GMT

Yes LED5 is blinking slowly:

The usb is not instantiating. So how do I proceed?

Thanks

RE: DK 52840 - Hardware failure

carlberg74 — Thu, 09 Jul 2020 23:28:40 GMT

Dont know if it helps.. but you can try this:

Have the power on, battery in place, the power slide in USB and the USB cable connected. (not thing will happend)
Now hold down Boot/Reset button and slide the power slider to VDD (from USB) and then the Bootloader drive should pop up on your computer and the LED will start flashing slowly.

RE: DK 52840 - Hardware failure

David K. — Fri, 15 May 2020 12:14:09 GMT

Thanks for your support !

RE: DK 52840 - Hardware failure

Jørgen Holmefjord — Fri, 15 May 2020 12:08:28 GMT

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.

RE: DK 52840 - Hardware failure

David K. — Thu, 14 May 2020 11:25:28 GMT

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

RE: DK 52840 - Hardware failure

Jørgen Holmefjord — Thu, 14 May 2020 11:00:18 GMT

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?

RE: DK 52840 - Hardware failure

David K. — Mon, 11 May 2020 15:26:09 GMT

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,

RE: DK 52840 - Hardware failure

Turbo J — Mon, 11 May 2020 14:30:12 GMT

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:

Download the "Interface MCU firmware" from the DK's download page (.bin File).
Hold reset button and power on DK (by pluggin it into USB)
Put the bin file on the newly opened USB drive - Do NOT PUT ANYTHING ELSE THERE!
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.