DK nRF52832 no longer works

[UDT]

Hello !

I'm currently working on a project using the DK Boards nRF52832.

I'm disappointed that one card no longer works ( doesn't light up). I therefore explain to you the tasks it performs. 

The card plays the role of a central. I'm currently using 6 peripherals. In the future, the objective of the project would be to use 100 peripherals and 1 central. In the initial state everything is initialized and the program waits for a command from the Uart. As soon as the central receives the command from the computer, it launches an RTC and it begins to scan and search for peripherals. Once it finds one, it performs the following tasks:

• read the btid
• discover services and characteristics
• read the value ​​of 3 characteristics
• send all data to computer via Uart
• disconnects

It performs this loop for the 6 peripherals, it waits for 1 min, and then restarts its execution until it receives the Stop command from the computer. The execution can last 3 to 4 hours. 

Would that be a lot for one board? Could this be a reason for overheating and burnt out? 

Thanks for your help !

[Jørgen Holmefjord]

Hi,

The board should not have any problems handling this load or length, as long as the chips are used within the specifications, they should normally last many years.

Is there no light on LED5 on the DK, or are you referring to the application LEDs (1-4)?

Have you tried a different USB cable or connected it to another PC? Do the board enumerate as a removable device on your PC when connected?

Best regards,
Jørgen

[UDT]

Hi,

Thanks for your response.

I’ve tried all of your suggestions. Even tried to turn it on in Boot mode. The card isn’t detected by the computer at all, and no led is on.

In addition, the card heats up a lot at the PCA10040, and the current passes well in the pins (a voltmeter displays 4.83V connected between the GND output and 5V).

Do you have any other assumption ?

Best Regards.

[Jørgen Holmefjord]

If the board heats up, there could be some short circuit somewhere. Have you made any modifications to the board? Can you upload pictures of both sides of the board?

Are you powering the board through USB, or through external supply?

[UDT]

I've made no modifications to the board and I'm powering it through USB.

[Jørgen Holmefjord]

Hi,

Sorry for the slow response. Which part of the board is heating up? Is there a specific chip on the board that gets hot? Do you have an estimate of the temperature?

I checked with our board designers, and they had not experienced this issue before.

Best regards,
Jørgen