Chosen Solution
My computer normally boots up correctly, but will then hang anywhere between a few seconds and about twenty minutes afterwards. Twenty five seconds after hanging, it reboots. It seems that the busier it is, the longer it takes to hang, and I suspect that the problem is temperature-dependent, but it is hard to tell.
You’ll need to create a bootable drive to run it properly. Clearly the shoe cobbler can’t fix your shoe while you are wearing them. That holds true here as well. Which is why you need to use a different drive to boot up under. OK, How?? First you need a USB thumb drive (32GB) which you use Disk Utility to format with GUID and a journaled file system. Then go here How to get old versions of macOS to get the El Capitan OS installer and then run it to prep the USB drive. Or, follow this guide to setup the USB drive How to make a bootable OS X 10.11 El Capitan installer drive The last step is making sure you’ve booted up under your external Use the Option key when you restart to get to the Startup Manager to select it. Reference: Mac startup key combinations
Hey David,There are a few possibilities. I would try to diagnose it using another hard drive first. Hook up an external hard drive that has an OS and boot from it and see if the issue is resolved. If it is resolved, then its data related (hard drive, or hard drive cable, or OS, or a combination of these) You can report back here and hopefully we will figure it out :)
