How does one determine what is causing kernel panic on attempted boot?
Serial Number: W87130ZKVGN
Type: iMac "Core 2 Duo" 2.16 24-Inch (T7400)
Intro.: September 6, 2006
Disc.: August 7, 2007
Model: A1200 (EMC 2111)
Family: Late 2006 - 24"
RAM: 2 GB
VRAM: 128 MB
Storage: 250 GB (7200 RPM)
Optical: 8X DL "SuperDrive"
All attempts to boot the system from any media result in a kernel panic.
What has been tried
* Checked that it makes all the right "chime" noise on startup, before the apple and spinning gear.
* Booted into single user mode and was able to access hard drive file system without errors. Was able to mount the HD as read/write and run standard repair/diagnostic cmds from the command line. Also ensured permissions were correctly set. Suspect the hard drive is actually OK, but still could be corruption of O/S boot files. Not sure if this would cause kernel panic when booted from CD with HD still attached.
* Holding down option key on startup works OK. Shows the partitions on the hard disk and other O/S boots available on recovery partition, USB or DVD. It will try to boot off selected item, but fails with kernel panic.
* Holding down shift key on startup shows the progress bar and completes that phase, but kernel panics prior to displaying menu.
* Holding down D key on startup works as previously noted. Extended diagnostics show no errors.
* Holding down command V (verbose mode) works to the extent of showing boot process, but eventually kernel panics.
* Resetting SMC and PRAM doesn't help.
* Prior to this the unit didn't give any indication that any hardware was failing or software was corrupt.
* Disassembled and inspected unit for any obvious loose connections or damaged components. Found none.
* Pulled the hard-drive cable and verified that I got a file folder with a flashing "?" on startup.
* Tried booting from DVD with HD cable disconnected. Still causes kernel panic.
* Swapped various amounts of RAM in and out, plus tried running on just one of the two slots without any success.
Originally suspected just a bad hard drive, because of only getting as far as white screen. Subsequent testing with the original install disk indicated that the actual issue was a kernel panic, since a text message to restart the unit was displayed.