Samsung Galaxy s6 Won't Charge

I dropped a Samsung Galaxy s6 in a sink filled with water, and pulled it immediately. I didn’t even try powering it up, ordered a replacement battery and worked on disassembling it. The little Ifixit heating pad didn’t work at all; a careful application of my heat gun did the job easily. Replaced the battery and carefully cleaned all the internal connection points. Also unplugged all the internal connectors to the motherboard and cleaned everything with acetone. Put everything back together, and it won’t charge, at least according to the charge indicator LED. I’m equipped to do surface-mount work, but replaced the entire motherboard instead. Also carefully cleaned the micro-USB charge port. Still no indication of charging. Any ideas?

Thanks,

—Pete Young