MacBook Pro sleeps unexpectedly and runs fans at high speed, even after SMC reset My MacBook Pro (15 in Retina, early 2013, macOS 10.14.5) sleeps unexpectedly, although there is enough charge in the battery. To wake it up, I must connect the power supply. Furthermore, the fans run at high speed every now and then, even though the MacBook isn't under heavy usage and is properly ventilated.

I reset the SMC according to these instructions: https://support.apple.com/en-us/HT201295, but the problems went on. I checked the computer with EtreCheck (core version) and coconutBattery; both detected no issues.

What else could I try?
Run diagnostics on the Mac as follows:


Disconnect all external devices
Go to Apple Menu —> Restart
Immediately press and hold down the D key while your Mac restarts
Keep holding the D key until you see the screen listing different languages appears
Click English.  Apple Diagnostics starts automatically.


Common results could be:


Wi-Fi — a failure of the AirPort wireless card (4AIR)
Hard disk and SSD (4HDD)
Logic board (4IRP)
Memory — RAM (4MEM)
External disk (4MHD)
Fans (4MOT)
Processor (4PRC)
Video/graphics card (4YDC)


I'd recommend you see if you have a fan issue: 4MOT