I had the same issue with my New JBL Boombox..White LED is turning on when charger connected and device start up with start up sound.. No other functions were working.. Straight turn off when unplug the charger..
Tried many JBL reset attempts.. But was unsuccessful..
Thanks for the above answers..
I pressed the “JBL Connect" button ( Not the Bluetooth) and Volume + button together while charger is on for 10 Sec. Unbelievable….!! Unit turn off the power.. Removed the charger and turn on power as usual.. All good now.. All functions are working..!!!
Thanks again Guyssss …
Very happy and Enjoying my Boombox again..