Cowon J3 MP3 Player Repeated Reboots Fix

I own a Cowon J3 MP3 player. I love it. The music it produces, heard through a higher end set of cans (I own a set of Ultimate Ears TripleFi 10 and a pair of Audio Technica ATH-M50 headphones, both of which re-produce beautiful music) is dreamy. Any other MP3 player simply pales in comparison. This is mostly due to Cowon’s advanced JetEffect audio enhancement technology. As long as the player works, it is a charm.

Cowon J3
Cowon J3

Creative Commons License photo credit: NFS-974

While setting it up, I had read about nightmares with Mac OS X and this player and how it should not be plugged into a Mac. Well, me being a technology jerk, decided to do it anyways and ended up with a player that constantly rebooted itself. It would get to the bootup screen, perform a “checking albumart” function and then throw garbage on the screen. The J3 does not have a hard reset built in and I tried every other trick I knew of. I knew that I would have to do something drastic.

I found a post on that explained how to use tcctool to unbrick the Cowon J3. From what I understood, most of the people that ran into this issue were able to mount their players on a Windows machine and fix the bad file that was causing the issue. In my case, the device would not boot far enough for me to use any such trick. So I ended up using tcctool to upload the latest firmware as explained in the post above. However, I still could not boot it up. It would still cycle through endless restarts.

So instead of uploading the latest firmware, I decided to upload the oldest firmware I could find on the Internet. That did the trick. I installed Cowon J3 Firmware Version 2.10 on the device and it restarted just fine! I then proceeded to fix the bad file by formatting the drive and re-uploading my music. It worked like a charm.

So if your Cowon J3 is stuck in a never ending loop and you are brave enough to try the tcctool method, it might be worth a shot. Of course, no warranties are implied or offered with this advice. Please make any changes or fix your device at your own risk. Leave a comment if this helped or if you need more information.

I just love having my little player back! 🙂