drivers – Installing a Backlight in a Laptop and Motherboard Voltages

I’m rejuvenating an old machine and upgrading the fluorescent backlight to an LED strip because the tube has aged after 10 years and the inverter powers down after being on for 10 minutes or so. The new LED driver module requires a 9 to 28 volt supply. I think I’ve established the functions of the pins in the connector feeding the existing inverter, however the Vss level appears to be 5 volts. Do some machines use this lower voltage for inverter power? I can’t find any data about motherboard voltages on the laptop (A Toshiba Satellite Pro L300). Can I tap into the 19 volt incoming power from the “brick” after fuses before it feeds voltage regulator/charge management ICs, or would that be wise?. (the inverter appears to have an SMD fuse).
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