IMac – Kernel: “Previous shutdown cause: -62”

We have a small group of 2012 and 2013 retina MBP and only one in the group has the -112 restart cause logged when it freezes in a hard manner. The rest have never once froze hard or shut down/rebooted spontaneously.

No diagnostics from Apple show a specific failure - the SSD has been tested extensively and doesn't have any other errors that fsck lists or corrects (other than the typical minor and correctable filesystem corruption that a hard reboot causes).

In the last 3 months, it has logged two -112 restarts and two -128 restarts.

If you paid for AppleCare - take it in and get it repaired. If you have to pay for a repair, it will likely be the $300 to $400 flat rate repair where they send it in for factory diagnostics and overhaul.

It appears to be battery related. It may be related to -103, however both indicate that you should check the battery. Try running the laptop from the charger and see if the laptop still unexpectedly shuts down. Also check to see if there are any spurious sensor readings for the battery using iStat Menus or equivalent which may indicate the laptop trying to protect itself by shutting down.

-103
Battery cell under voltage detected.
Check battery.

-104
unknown
Check battery.

^{Source: Shutdown Causes}