Chosen Solution
This is WEIRD! I installed a fresh clean MacOS High Sierra on my MBA 2015. Worked fine. I then turned the mac off and left it for about a month. I came back to it just the other day, and it won’t turn on. Plugged in charger - green light at first, then red light. Ok, I thought it’ll charge a bit and turn on (even though I do remember turning the mac off before I left for my break). Came back after 30 minutes. Still won’t turn on. Thought it was the charger. Plugged in another charger (which works for sure). Same thing. Weird. Did all the reset BS that I found online (SMC, SM-this, SM-that, PM, PR, all that stuff). Nothing. Opened it up for inspection. Looks like it’s brand new (seriously - I take care of my stuff like crazy! A bit OCD on these things). Disconnected battery and reconnected it. NOTHING. What gives? Anyone here has a clue? Here are some pics: https://imgur.com/uLsVAtI https://imgur.com/Bq8cob3 https://imgur.com/G3A3BVf https://imgur.com/a/MEAYUBB
With Mac unused and unplugged for a full month, what might have happened is that battery reached its heaven and went bad and unable to take charge any longer. First step would be to try and disconnect the battery and see if that gives any change and Mac would be able to start on its own when plugging in the magsafe. If it starts without the battery then a battery replacement may probably solve all issues, otherwise we get into machine hardware failure that would need more or less blindfolded parts replacements to progress any further with troubleshooting.
