I have a J-Link that I've used successfully for years over USB. I recently used J-Link Configurator to assign it an IP address and can no longer communicate with the device, either through USB or IP.
Configuration:

• Hardware: J-Link ARM Pro, version 3.0
• Software: J-Link ARM V4.84
• Environment: Windows 7

In detail, here are the steps I went through:

1. Plugged J-Link into a USB port on my PC
2. Ran Configurator
3. J-Link was detected by Configurator
4. J-Link firmware was updated to the latest revision
5. Right-clicked on USB emulator, selected 'Configure'
6. In the 'Configure J-Link' dialog:
7. Selected Manual IP configuration
8. Entered IP address, subnet mask, and gateway
9. Clicked OK
10. A dialog appeared stating "J-Link successfully configured. Please unplug and reconnect the J-Link before pressing OK."
11. Unplugged USB cable from J-Link
12. Plugged USB cable back into J-Link
13. Clicked OK

After doing all that Configurator was no longer able to see J-Link over USB, and:

• There is no evidence of J-Link in Windows Device Manager
• The middle (of three) J-Link LEDs is solid green regardless of whether target is powered or not

If I set up this J-Link with Ethernet and USB power cables:

• Cannot 'ping' J-Link
• Cannot bring up J-Link web page in browser
• The middle (of three) J-Link LEDs is solid green regardless of whether target is powered or not
• Configurator cannot see J-Link over IP

The J-Link IP address is on a different subnet from my PC, so it may be expected that it isn't visible in the Configurator TCP/IP window.

I have also re-installed the V4.84 J-Link software and rebooted the PC, all with no effect.

No, when I power off the J-Link and then connect it via USB the center LED comes on solid green without blinking at all.

Not having heard anything back on this issue, I borrowed another J-Link ARM Pro from a co-worker and attempted to assign it an IP address using the same procedure outlined above. I now have two J-Link devices that are unusable over USB or IP. Please help me understand how I can restore these two devices to service.

I have attached a file containing a number of screenshots of the exact procedure I just went through. The first four images are steps of using Configurator, and the final two images show Windows Device Manager before and after. In detail, the six screenshots in this file are:

1. Configurator dialog showing manual IP address being configured (I've smudged out all J-Link serial numbers)
2. After clicking OK in the above dialog, the new dialog requesting I "unplug and reconnect"
3. Warning dialog after unplugging and reconnecting the J-Link USB connector
4. After closing and re-opening Configurator, showing no USB J-Link devices found
5. Windows Device Manager (prior to assigning an IP address) showing J-Link driver properties and USB hub with J-Link attached
6. Windows Device Manager after unplugging and reconnecting J-Link USB, showing no J-Link USB device present

Prior to the IP address assignment, my co-worker's J-Link would flash the center green LED quickly for 1-2 seconds before coming on solid. In addition the left-hand (outbound) LED would come on solid green. After the IP address my co-worker's J-Link acts like mine: the center LED simply comes on solid when plugged in, and no other LED is lit. My co-worker's J-Link is also a J-Link ARM Pro, version 3.0, with firmware upgraded to the V4.84 release.

My co-worker is understandably miffed that I have bricked the J-Link he has been using. I'm happy to answer any further questions you might have and look forward to your assistance.

Welcome back and thanks for the reply Alex!

Yes, I did only have one J-Link device connected to my Windows PC when the "unplug and reconnect" problem occurred. (I've only one USB cable with a standard-B plug anyway.)

Regarding J-Link serial numbers, I noticed that screenshots in the Segger documentation smudge out the serial numbers, so I followed suit. My guess is that since a valid serial number is required to download Segger software updates it is wise not to publish yours for the world to see.

Speaking of which, now that I look carefully at the screenshots I uploaded, I notice that the 'USB Identification' field in the very first screenshot is 'USB 0', but in the second one (just prior to OK'ing the "unplug and reconnect" dialog) the USB Identification field reads 'SN XXXXXXXXX'. I don't know if that is significant or not.

I've downloaded the V4.84b release and will install it shortly. Perhaps I'll uninstall the old version first in case that might help with USB re-enumeration. I will also contact support as you suggest. Thanks again for your help.

- Tom