Hi,
I'm running Mac OS X 10.10.2 with the nRF51-DK PCA10028 card that I received today. I started off following the instructions in this article, and was able to get JLinkExe running. I was however not successful in running anything meaningful - not even blinky. I tried writing the blinky-blank compiled code to address 0 and then reading address 0 back, but I didn't get the program back. When I ran it, it just produced a HardFault immediately and ended.
So I turned to mbed instead. I logged on and got set up with an account. I was instructed that I needed to install the mbed firmware, which I attempted to do according to the instructions. I downloaded the latest (0218) mbed firmware and did the IF BOOT/RESET procedure. The BOOTLOADER drive appeared, but Mac OS X would only mount it read-only. So I ran "sudo mount -u -w -o sync /Volumes/BOOTLOADER" in hopes of making it writeable, and it appeared to work. However, when I then copied the file over, the LED flashed as advertised. I rebooted the card and nothing happened. No LED, no regular drive mounted, nothing.
After some tinkering around trying to get mbed to work I figured I'd go back to JLink. So I downloaded the JLink image off the download section of the product, version 141128, and followed the same procedure to get it installed. This time my computer froze up, and eventually the process was somehow aborted. It still wouldn't boot.
As a last-ditch effort I also tried a Windows installation I have, in order to attempt to properly mount the drive, but to no avail.
Now nothing works. The IF BOOT/RESET procedure does nothing. The LED is completely dead. I've cycled everything, with and without the battery. I would expect some kind of warranty to cover this, as I've only followed official instructions. Help?