e45bt have been broken for a while now but I want them to work again

I need help because my e45bt have been broken for a while now but i want them to work again they charge fine and with the JBL charger like the red light turns on and all the 3.5mm jack in the headphones work like i hear sound from both sides but when I try to turn on the headphones they just won't turn on not even a white or blue light i have taken them apart to see if there was something wrong with them but i couldn't see anything broken or burnt