frequent reboots. Hardware diagnostics won't run
computer auto reboots several times a day. Attempt to run diagnostics by pressing 'd' on startup, 'starting internet recovery' followed by a warning with a big '!' (exclamation point) and Apple.com/support -3403D.
Appended is a report from EtreCheck. I'm not too worried about the battery, as the MacBook is used as a desk top, and is always plugged in. Probably not a cause of the rebooting.
OK, it's 10 years old and considered 'obsolete', but since it works adequately for my purposes most of the time, not ready to pony up $2K for a new one if that can be avoided.
Most likely main issue to address is Runaway process - A process is using a large percentage of your CPU. Also under 'top processes snapshot by CPU, is Other processes 353.80 % (?)
How is that possible?
Can pay the $15 for the pro-version of EtreCheck, but thought I'd see what comes up from the community first.