(cont) I measure 0 voltage between any of the black wires to any of the white wires. The red measures 11.26 volts to the first white wire, 11.26 again to the second white wire, and 15.28 volts to the third white wire.

FYI, When I pulled out the battery compartment: Both reds seemed to be connected to each other, and both blacks to eachother. Voltage between reds and blacks was 15.45 volts. Had been charging for 24 hours, though the unit stated it was ‘about half full’. Suspect the batteries are fully charged and in series? (15.45 / 4 cells = 3.86 volts per cell)

Theres a second smaller ribbon cable on the underside of the board on the left in my model, for a total of *3* ribbon cables that need to be disconnected.