Why does the MacBook suddenly power off without warning?
The MacBook works in every way normally - boots normally, passes Apple Hardware Test with no errors, is normal to use… except it suddenly powers off, pretty much at random.
This sometimes happens during booting, sometimes happens within a few minutes of starting up, and sometimes happens after a period of using it. Intense processor use, and the heat of the MacBook, seem to make no difference (at least I cannot work out a pattern).
This has happened under two different versions of macOS, and using two different hard disks in the machine, and also having replace the SATA cable to the hard disk. The same happens when booting from a hard disk connected via a USB port.
Also going to Console and checking the logs does not reveal much that is helpful - here are the logs from the last two times it has happened: https://pastebin.com/EJkiS5v8
When the computer suddenly powers off, a light sort of click/thud noise is heard. The MacBook will then reboot normally straight away.
This looks likely to be a hardware problem (a damaged logicboard?) but any further tips would be most welcome!
Is this a good question?