nRF52840 DK Evaluation boards are getting fail when we powered through J2 Micro USB

[Srinivas V]

Hi Team,

nRF52840 boards are getting fail continuously not able detect by Host computer.And the boards are no more useful and all boards are brand new only One day we have used.

Some of the observations I am sharing here.

1. When we connect through coin battery SOC led is blinking and when we connect through J2 USB not blinking. All the Power Switches are selecting properly (SW8 = ON, nRF Power source SW9 = VDD, SW6 = default) 

2. When we connect through J3 USB , SOC is working fine but not able to connect to External debuggers.

3. When holding RESET and powering the board on, LED5 is blinking slowly but there is no mass storage device named "JLINK" or "BOOTLOADER" detected.

4.How to detect weather it is cable problem or some thing else , is there any standard for that USB cable to use for DK board, like ampere rating and other parameters.

Any guidance in terms of alternate power settings that will fix this issue, or any cable changes are required to make it work, within one week we lost 3 boards, we haven't done any changes in HW.Even though we are not touching the board while powering up.

Regards,

Srinivas

[haakonsh]

If this has happened to several DKs you need to check the USB cable and the USB port on the PC you're using. Try swapping the cable with a different one, the same goes for your USB port, use a different one and make sure that it is not through a USB hub. 

[Srinivas V]

Hi Haakonsh,

Thanks for your reply. 

It happened to several DK's but not with same system means for different people with different systems(Laptops) with in my team within one week time.

We have tried with several options like the way you mentioned , different USB cables with different ports but not through a USB hub.

For some boards it is working fine with 2 months , suddenly happened. My case i have used only one day.I am getting bad with Nordic on these issues.

Is there any way we can identify this root cause , why means going forward we are going to use same boards (nRF52840 DK) with more number for our development purpose, if the same issue continues we need to choose other option.

Could you please take it as high priority and any Hardware expert engineer going to support this issue , it is very much helpful to us.

We are from Global MNC(UTC), and nRF52840 DK is used by several teams for our R&D Purpose, previously we used to use TI Controllers ,now we have migrated to NORDIC.

We are expecting more help on these issue.

Regards,

Srinivas.V

[haakonsh]

Hey Srinivas, sorry for the late reply.

Can you power the board through the External Supply, P21? 

How many boards are affected?

[Srinivas V]

Hi Haakonsh,

Thanks for your reply. Total 5 boards were affected. Some boards are brand new and some boards we have used only one month. 

We haven't find out the root cause, we are not suspecting either cables nor usb ports, why means rest of the peripherals working fine like mouse, BLE Dongles  etc.. 

For one new board we have connected only one day, second day we connected and not detecting at all, we did the recovery mechanisms like Loading J Link bin file in BOOTLOADER mode, it is taking the file but after that also it is not detecting the onboard debugger.

Is there any special settings required to power up the board through External supply (P21), like other switch positions any jumper settings.

If anyone had any idea on these issues, it will be more helpful to us or any other recovery mechanisms also fine for us.

Regards,

Srinivas.V

[haakonsh]

Srinivas V said:

Is there any special settings required to power up the board through External supply (P21), like other switch positions any jumper settings.

 Yes, but you won't be able to use the debugger, so I think we have to try something else. 

What voltages do you measure on the VDD and 5V rails when you power the board through the J2 USB connector? 

Did you buy these DK's from a trusted electronics distributor?