Error, when I typed the below info in an earlier post....., I meant to type System Management Controller SMC,.......rather than power management. My error. Both however refer to system control/power Mgmt. But still 😊
***As to the 2013 Air, this is most certainly a conflict between the power management & Haswell processor; also conflict in the battery output which starts / causes initiation towards the Sleep Cause: 5
Of the 3 limited causative "issues" with a small (relatively) number of Macbook Air, that being:
A: wifi issue (not really an issue, but a protocol setting conflict between old routers and new 802ac wifi) issue already solved
B: sound fluctuation issue issue already solved
C: sleep/blackout issue..............
B and C have both been power issues. I diagnosed B problem early on as a power variance tolerance in the speaker assy, since a power boost from a 3rd party sound boosting APP fixed the issue,.......as such Apple issued a patch for this issue which accounted for the "razors edge" of power-pass to the speakers that was causing the problem in a limited number of Air. Software fix. Issue Issue already solved on B
C: When not directly related to Chrome, is also another power issue, with a likewise software/firmware patch.
In making the Macbook Air the King of long-life battery run-time, ...a few tolerances were walked "along the edge" wherein a small number of Airs on issue B and C didnt pass.
So, 2 power issues (B and C) fixable (B is already fixed) with a simple patch and a wifi protocol issue.