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
JBL Flip 4 Main Board/ Speaker/ Charging AUX Port Replacement Part | eBay
Jbl Flip 4 Motherboard - Speakers - AliExpress
High Voltage Battery Motherboard Computer Chip 1047340-02-C Tesla Model S 2015 – Pacific Motors