fatgonzo 0 Posted January 17, 2017 Hi. I have a bit of a problem with a JM4. When I turn the unit on, it says "NO FIRMWARE IN UNIT". followed by "INSERT SD-CARD TO UPGRADE FIRMWARE". However, firmware upgrade doesn't work. I have tried to start flashing the firware with several SD cards with several file systems, but nothing happens when I insert SD card. The unit has no warranty left. I had the same kind of thing happen to a brand new POD HD500X when it came out. I got a replacement for that from warranty though. This looper on the other hand, having no warranty left and no way to flash..any ideas? Quote Share this post Link to post Share on other sites
KARMAK 0 Posted October 29, 2017 Hi. I have a bit of a problem with a JM4. When I turn the unit on, it says "NO FIRMWARE IN UNIT". followed by "INSERT SD-CARD TO UPGRADE FIRMWARE". I had the same problem yesterday. I just followed the instructions provided here: http://line6.com/support/page/kb/_/effects-controllers/jm4-looper/jm4-209-update-instructions-r397 and the problem was solved in two minutes. The tricky part is to find a suitable sd card (1-2gb) Quote Share this post Link to post Share on other sites