So, I have this old JBL Flip 2, it didn't turn on, that was an easy fix, however, it stopped producing audio, I hooked up the speakers directly to my headphone jack
1PCS For JBL Flip 4 Bluetooth Speaker Motherboard E322002 CX-0812W - AliExpress
1PCS Original Board Connector Main Board For JBL Charge 3 GG TL Bluetooth Speaker Mainboard