Chosen Solution
I just got this 2015 MacBook Air with a coffee spill. Upon internal inspection, there was definitely some coffee near the trackpad and battery, and by the IO board as well. The only moisture indicator that was red was the one on the flex cable connecting the IO board to the MLB. Initially, the MacBook would not run without the charger plugged in (though the battery does charge) and it would not detect the SSD. I thoroughly scrubbed everything with a brush and 99% isopropyl, and now I’m installing OS X on the ssd, but I’m not able to power on the MacBook without the charger connected. The MagSafe indicates when charging and when fully charged. I’ve attempted SMC reset and NVRAM as well. Could this fault be repaired by a replacement IO board? Update (08/08/2016) Thanks for the advice Dan. I’ve never seen coconut battery recognize a battery that OS X doesn’t. Is there some other function of coconut battery I don’t know about? As the gods smile upon me, the thorough cleaning and battery replacement did the trick. All is well!
No, nothing hidden in CoconutBattery ;-} In your Q you stated you could get the system to boot up under the MagSafe charger which is why I wanted you to run CB. It’s not the OS that sees the battery it’s SMC services which CB polls by way of OS calls which can help us figure out whats happening. Sounds like your good here! Happy it all worked out.
