Connected to DK, no response

[lewis]

I have two 52840DK, which can be used before, but I took it out and used it today. The led light on the rear panel of the USB is not lit, and the computer can't detect the port. I tried to use the onboard battery to power it. There is a board with a led light that can flash, and the other still has no reaction. What is the problem? How can I solve it?

[Martin Lesund]

Hi Lewis,

Could you go through the list in this thread?

Did the boards power up with the battery supply?

How do you flash the boards?

[lewis]

I use the mac to connect my device, I make sure that the JLink driver is installed, I try to replace the computer, the system is windows10, the device management list shows the unknown device, I think the computer should be no problem, I should use the usb charger separately. Powering the dk, the signal indicator of JlinkOB is not lit. I have encountered this situation before, thinking that dk is damaged, but it is better the next day. It didn't take long for this problem to reappear.