Chosen Solution
I dismantled & cleaned everything. There was sticky flow residue running from left side of logic board from vent down to battery. Slight greenish corrosion on keyboard backlight terminal, but otherwise looked in decent shape. None of the moisture damage indicators have turned red on the logic board, but the battery PCB is bright red & won’t charge nor run from battery. She won’t boot from the SSD, but will boot from an external drive. SSD gets immediately too hot to touch, and the fan runs at max velocity. Also, the fan won’t run w/ SSD removed. My DIY dilemma is determining whether the PCIe circuit has been compromised. I don’t want to install a replacement SSD if there’s a possibility of frying another drive. Anyone able to test if fan starts at boot w/o SSD? Not an electronics guy & having brain pain from trying to decipher schematic. Lots of nearly microscopic stuff in there. Sheesh!
Sounds like the SSD is shorting to ground if it is getting hot. Very likely a new SSD will resolve this, haven’t come across one before where the SSD was shorting, and it was a something on the logic board causing this. On this model, the fan only spins if the MacBook thinks it’s getting hot, it doesn’t spin all the time like older models (yes, it’s strange). The shorted SSD is setting off a sensor issue, since it is shorting to ground, which is why the fans run full speed. Again, a new SSD should sort this. Not charging/running off battery will be because of the corrosion. Thoroughly check the board for any corrosion and clean it using a brush and isopropyl from the logic board and battery board (unplug battery from logic board whilst doing this). Chances are the battery is dead however, and needs to be replaced. Could be something else with the charging circuit on the logic board, but I would say it is the battery if this is where the corrosion is. The 2013+ MacBook Air and Retina models use the same SSDs (although I think the 2015’s have a slightly faster drive, but the older models will work in the 2015 model). If you know anyone with these models, ask if you could try the SSD inside to make sure before ordering it, since it is an expensive part.
