Battery not recognized, SDA/SCL resistors seem okay?

Got a Mid-2012 13” 3115-B MBP board that won’t recognize a battery, nothing seen at all in the system or reflected by the battery indicator. Saw that similar symptoms of computer still running briefly after disconnecting the charger, fading power light/fan spinning after etc. often indicated a battery detection issue issue thru the SMC, specifically in the resistors R5280/R5281.

Measured 3.42v and 3.42v on R5281, which compared well with a working machine on the same resistor. R5280, however, measures 3.42v in and ~1.7v on the SDA line, which on a working machine shows 3.42v on both.

Tried replacing that resistor with a checked good one, still got 1.7v on that line. Both resistors measure well in resistance, around ~2kΩ. Board had very minor corrosion on some vias/resistors on different parts of the board, all cleaned off easy. Not sure where the next place to look is?

Took off U7000 to look for any corrosion on the pads, didn’t find any, retinned and resoldered; no dice. Trying to sense some heat on the board to find anything shorted, but not finding anything concrete.

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