nRF52-DK Non-responsive

[Emlyn]

I have been using a NRF52-DK board to develop a BTle solution for the past week.
Today, midway through a debug session, the board vanished from my BT interfaces.

It also no longer shows up on USB when plugged in, neither directly or when attempting to put into DFU mode (holding the reset button down and powering on over USB).

Is there something in software I can do, or is this a hardware fault somewhere?

LED5 is not on.

Nothign is seen on USB.

[Asbjørn]

Hello Emlyn,

Q1: Did you have something external connected to the DK at the time? 

Q2: I assume you've checked the power switch, but are you able to check the voltage on the DK? Since LED5 isn't lightening up, it indicates that there isn't power coming to the board.

Q3: USB connection, is the USB port ok? Does it work with other boards?

Best regards

Asbjørn

[Emlyn]

Q1: Only the USB was plugged in.
Q2: Yes, also looked at voltages. All rails are at expected values and looks like the the MCU is non-responsive.
Q3: USB port is fine; other devices work, nRF52-DK is non-responsive in other ports.

Any way that the application processor software could affect the MCU on the board?
LED5 lights _very_ briefly on power up but remains off otherwise.