NRF52833 DK not powering up

[chethans]

Hi,

We have 4 NRF52833 DK being used for our development work.

Among that, 3 of them have stopped working and are not powering up.

They power up some times when connected to a power source for a long time, after 30 minutes or so. But this is rare.

Its very frustrating behaviour. We even got a new DK just couple of weeks back and it is also showing the same behaviour.

What could be the reason for this?

Thank you,

Chethan

[Simonr]

Hi Chethan

This sounds very strange. How are you powering these DKs? Are they not powering up if you're connecting it via a USB cable from the computer to the J2 connector on the board either? Have you made any modifications to these boards?

Also, please make sure that all onboard switches are in the correct position. nRF power source should be set to VDD. VEXT->nRF should be set to OFF, TRACE should be set to Def, and nRF ONLY | DEFAULT should be set to DEFAULT.

Best regards,

Simon

[chethans]

Hi Simon,

All the switches are in correct position.

We have not done any modifications to the boards.

Its a very strange problem indeed, I have not faced anything like this with previous NRF51 and NRF52 boards.

We are seeing the behaviour of dev kit powering up after keeping it connected to a power source for ~30 mins consistent across all boards. Sometimes they make a high frequency sound (barely audible) after powering up.

Thank you,

Chethan 

[Simonr]

Please fill me in on how exactly you are powering these boards? Do you have to connect them to a computer with a USB cable for ~30 minutes before they power up, or are you using an external power source of some kind? If you're using an external power source, how much voltage are you applying to the nRF52833 DKs, and what header/input are you applying this voltage to? Are you able to capture this high-frequent sound on video by chance?

Best regards,

Simon

[chethans]

Hi Simon,

The boards are connected to a laptop with a USB cable for ~30 minutes. Once it powers up, it works fine for the complete day. After a period of inactivity, this occurs again.

Connecting directly to a power plug via a usb adapter also does not power up the board. We have not tried this for long duration like above.

I will try to capture the sound when it occurs again.

Thank you,

Chethan

[Simonr]

Please update us with a capture of this noise when you can. I asked around and a colleague seems to be familiar with this issue. It usually occurs due to powering off and on the DK quickly. If you leave it off for a few (~10) seconds before turning it back on. Just try this a few times and you should see the DK working as intended. Please don't power the DK boards on and off rapidly as this should be what causes this issue.

Best regards,

Simon