Persistent kernel panics (even in Safe Mode, disks not the cause)
I acquired this Mac second hand and am trying to repair it, and am faced with persistent kernel panics, but in circumstances that are not quite similar to other posts about the topic.
What happens booting normally?
Start up sound is normal. Fans start. Apple logo appears. Start up progress bar advances just over half. Screen flicks through black to all grey, and nothing further happens.
What happens if booting from an external hard disk, or USB stick?
Exactly the same - bar advances, then screen goes grey. I also disconnected the internal hard disk altogether and this made no difference - still impossible to boot from any other device. I am pretty sure drives are not causing this.
What about other peripherals?
All are disconnected. I have even tried this with no keyboard and mouse connected, and still the same.
What happens when booting into Safe Mode?
Kernel panic text appears above the grey screen, with the Apple and start of the start up progress bar still showing (full text of the kernel panic below)
NOTE: this pic says CPU 2. Sometimes the Kernel Panic says CPU 3 in all instances too.
What happens when booting into Single User Mode?
Shown here (I am not keen to type all this up! But there is no way for me to recover it as text!)
Is the last line significant?
- [IOBluetoothHCIController][SearchForTransportEventTimeOutHandler] -- Missing Bluetooth Controller Transport!
In light of that line I disconnected the Bluetooth card and that too made no difference.
What about Apple Hardware Test?
Passes all tests. No errors found.
What about diagnostic LEDs on the logicboard?
All four of them illuminated.
What about memory?
I have read that RAM that is wrongly seated, or has degraded, can cause this. I even bought an extra SODIMM and took all other memory out of the machine and that did not solve it.
What about the SMC and NVRAM?
Yes, I reset those too. No difference.
Any light that anyone can shed on this would be excellent! This looks like some hardware problem that is NOT a hard disk or memory, but what is it then?
And finally here is the text of the Safe Mode Kernel Panic:
panic(cpu 2 caller 0xffffff8000bcae5): "Process 1 exec of /sbin/launchd failed, err no 2"@/SourceCache/xnu/xnu-2782.40.9/bsd/kern/kern_exec.c:4033
VM Swap Subsystem is ON
FireWire (OHCI) Lucent ID 5901 built-in now active, GUID c82a14fffe7bde94; max speed s800.
FWOHCI : enableCycleSync - enabled count going negative?!?
Debugger called: <panic>
Backtrace (CPU 2), Frame: Return Address
0xffffff8093c33df0 : 0xffffff800032ad21
0xffffff8093c33e70 : 0xffffff80007bcae5
0xffffff8093c33ef0 : 0xffffff8000796b02
0xffffff8093c33f10 : 0xffffff80007d9011
0xffffff8093c33f50 : 0xffffff8000327256
0xffffff8093c33f80 : 0xffffff800041756e
0xffffff8093c33fa0 : 0xffffff8000433c6f
USBMSC Identifier (non-unique): 00000000 0x5ac 0x8403 0x9833, 2
BSD process name corresponding to current threat: init
Boot args: -x
Mac OS version:
Not yet set
Darwin Kernel Version 14.5.0: Wed Jul 29 02:26:53 PDT 2015; root:xnu-2782.40.9~1/RELEASE_X86_64
Kernel UUID: 58F06365-45C7-3CA7-B80D-173AFD1A03C4
__HIB text base: 0xffffff8000100000
System model name: iMac12,2 (Mac-942B59F58194171B)
System uptime in nanoseconds: 1408457515
I did not have bootable drive with Yosemite handy, and finding a direct download for it proved a headache. But I did have Mountain Lion in my list of purchases in the App Store, so I tried that.
Everything worked perfectly in Mountain Lion.
So why not then simply have a go and upgrade direct from Mountain Lion to High Sierra?
This set off the longest, slowest, and most complex Mac OS upgrade installation I have ever seen - multiple different progress bars at different stages (even a wider, rounded end one that I have never seen), and even a loud beep noise at one stage that sounded the same as the one you get when RAM is faulty in your Mac.
But now, after an hour of waiting for it to complete, it all now works.
This is the guide I used to make a Mountain Lion bootable drive (it's a little different to later versions of Mac OS).
So try a downgrade to Mountain Lion, then upgrade to High Sierra - and it all looks good!
Is this a good question?