Chosen Solution
Hi there! Same problema here MacBook air won’t startup unless power button held on for long time. with my 2017 13" Mac Book Air. This happened all of a sudden and my problem is perfectly the same as written by the first user who had posted years before I did. What is the solution, pls? Thanks.
Your system is going into an SMC latched condition! Let’s get some better diagnostics of your problem as it could be a few different issues! First install this gem of an app! CoconutBattery take a snapshot of the apps main window and post it here for us to see Adding images to an existing question as often the batteries get long in the tooth. Second, I would run the onboard diagnostics to see if a firm error code is generated. If it does let us know what it is. To enter into diagnostics restart your system and press the D key to enter! Reference: Mac startup key combinations
