In terminal, run:
log show --predicate 'eventMessage contains "Previous shutdown cause"' --last 24h
| Code | Description | Notes and Possible Solutions |
| 5 | Correct shut down | That specific shutdown was started normally. |
| 3 | Hard shut down | If you didn’t force a shutdown, check the power button and make sure it isn’t stuck, etc. |
| 0 | Power disconnected | Unless you pulled the plug, check the power supply on an iMac. On a MacBook, this is either a battery issue or battery controller (logic board) issue. Try an SMC reset first, or a battery replacement. |
| -3 | Multiple temperature sensors exceeded the defined limit. | Run Apple Hardware Test or PC Doctor. Check fans/airflow/thermal paste. |
| -60 | Bad master directory block (badMDBErr). | Do not continue using the system, or you may face data loss: Back up data to Time Machine, completely erase the disk and reinstall macOS. |
| -61 | Watchdog timer detected unresponsive application, shutting down the system. | Probably an application issue. Retry in Safe Mode, investigate stuck applications, investigate startup programs. Run MalwareBytes scan. |
| -62 | Watchdog timer detected unresponsive application, restarting the system. | Same as -61, except the machine will restart automatically instead of shutting down. |
| -65 | Reinstalling macOS may fix this? | |
| -71 | SO-DIMM Memory temperature exceeds limits. | Swap memory if possible to see if issue persists. If so, check airflow/fans. |
| -74 | Battery temperature exceeds limits. | Perform SMC Reset. Possible need for battery replacement? |
| -75 | Communication issue with AC adapter. | Use an official Apple power adapter. If on a USB-C model, try charging with the ports on the opposite side (to test port failure on one side). |
| -78 | Incorrect current value coming from AC adapter. | Use an official Apple power adapter. Check building power/current at wall? |
| -79 | Incorrect current value coming from battery. | Check the battery connection. Check battery cycles (may simply need replacement). |
| -86 | Proximity temperature exceeds limits. | Check fans/airflow/thermal contact and thermal paste. |
| -95 | CPU temperature exceeds limits. | Check fans/airflow. Check thermal paste between heatsink. Reset SMC. |
| -100 | Power supply temperature exceeds limits. | Check fans/airflow on iMac. Check power adapter on MacBook, and remove any MagSafe 1 to 2 or similar adapters if in use. |
| -103 | Battery cell under voltage detected. | Replace the battery. |
| -104 | Possible battery issue? Try a complete charge cycle, or Apple Diagnostics before replacing. | |
| -108 | Probably memory related? Could be running out of RAM (and Paging fails). Can occur during sleep. | |
| -112 | Probably memory related? If on 2012-2013 15” MBP, probably GPU related. Usually occurs alongside -128. | |
| -127 | PMU forced shutdown. | Possibly fine if you performed a hard shutdown? If not, check power button (make sure it isn’t stuck). Otherwise, could be a logic board issue. |
| -128 | Same with -112. |