Hello,

We have a problem with a J-Link Plus that we bought last year. Part number is 8.08.28, version is 10.1.

Our problem is that the J-Link firmware fails to boot, so it falls back to a bootloader firmware that won't even accept USB connections, making it functionally useless. The only reaction we can get out of it is the first time we try to establish a connection with J-Link Commander, it'll detect that we need to update the firmware



then the update seems to complete correctly



but the new firmware fails to boot with the following message.



Here are some text dumps of the logs found in the above pictures (for search discoverability and easy copying) :


After this failed update cycle, the J-Link won't respond to anything, it just gets stuck on "Connecting to J-Link via USB...", which doesn't timeout even after a whole hour. When the J-Link is in this state, here is what the ShowEmuList command gives us:



Of course, our actual serial number isn't 123456. If we unplug it and plug it back in, we're back on square one: needs to update, "successfully" updates, doesn't work.

Speaking of plugging it back in, when we plug the J-Link into a computer, the status LED:

• is solid red for a second;
  
• blinks twice while still red, only lasts about a second;
  
• switches to a rapidly blinking green which goes away very quickly;
  
• ends up on a stable solid green.
  

Here's a list of configurations we've tried:

• 2 different USB cables for the J-Link;
  
• 4 different computers on Windows (7 and 10);
  
• different USB ports on a single computer;
  
• connecting both with and without a USB hub;
  
• manually changing the driver in the Device Manager;
  
• different versions of the J-Link tools (some older, some newer).
  

Is there anything else we could try, or does this look like an RMA? Any help would be appreciated.

Many thanks in advance,

Hugo M.

Hello Fabian,

You are absolutely correct, I'd been given the wrong information about which device had stopped working. The serial number I provided in my profile was correct and is indeed for the (seemingly) defective 2016 unit. The one we bought last year still works perfectly fine. However, we do have another defective J-Link Plus from 2014, serial number 609300932: would this unit also be eligible for the trade-in program? It's completely dead and has been since before I joined the company, its status LED won't even light up.

Before going forward with trade-ins and buying new units, I also need to double-check something with you. At least one of our units will need to be downgraded to an older version of the firmware, as per one of our subcontractor's instructions for managing and debugging the software they made for us. The exact version we need to go back to is 4.96m – we still have the setup files, no problem there. As much as I've read in the user guide that downdating is not recommended, should we still be able to do it in theory, or are the newer units absolutely incompatible with pre-5.0 firmwares?

Thank you so very much,

Hugo M.