The OZ8681L serves as the power management backbone for mobile devices, famously utilized in the Nokia 8800 series
: Found frequently in Lenovo IdeaPad and Samsung (NP series) motherboards to manage battery charging and SMBus communication. 8681l ic datasheet
If the 8681L has an EN pin and you leave it floating, the internal state is undefined. The device may remain off or oscillate. Always tie EN to VIN or a logic high. The OZ8681L serves as the power management backbone