Why do I get a kernel panic 2700 seconds (allegedly) after reboot?
Late 2009 iMac (11,1)
Installed 4x8GB FLEX DDR3, and these seemed to be working fine in OS X Yosemite. No beeping before or after situation described below has hinted at RAM failure.
Two weeks later I replaced original Seagate HD with Seagate ST2000DX001 2TB SSHD. Buggy result after reinstalling from Time Machine (freezing programs, iTunes and AppStore unresponsive), so I decided on a clean install of Yosemite from USB. One kernel panic during installation, but worked fine after reboot.
Everything seemed to be okay, so I tried an upgrade to macOS Sierra from AppStore. Massive fail with chaining kernel panic reboot every 5 minutes or so during upgrade. Installation did eventually complete, but the computer went into repeating kernel panic after a few minutes use - even while just being passively logged in.
According to crash log, the kernel panic always sets in 2700 seconds after reboot (though in reality the panic sets in much earlier). Is this a hint of something specific?
I have tried to
- Nudge RAM modules firmly in place
- Zap NVRAM
- Reset SMC
- Repair, First Aid, Erase HD before Yosemite and/or Sierra installation
- Installed Sierra from USB
I have not yet tried (but will asap)
- Removing RAM modules
- Testing HD in target mode with other Mac
Is this a good question?