Problem with kernel panic message - Cannot boot from disk or usb

Question

Hi Everyone,
I was wondering if someone could help me with a problem I've been trying to tackle for the last few days. I have a 24" iMac 2.33 Ghz Dual Core, with 2 gigs of RAM. A couple of days ago my computer crashed, and when I tried to boot up again I got the infamous grey screen kernel panic message ("You need to restart your computer..."). What's worse is that I get the same message when I try booting from my external drive and the installation disk itself.
I've basically planned on formatting since it's been a while anyway, but since I can't boot from my external drive or the installation disk that came with my computer these are not options at the moment. I can only get into the computer via safe mode. I've used disk utility to verify the disk, and it comes up with no errors. Anyways, I'd really appreciate if anyone had any advice on this. I've scoured the internet for advice about kernel panic messages, and they all suggest booting from disk or external drive etc., which is not a possibility for me right now.
Thanks

Answer 1

If you get a panic when trying to boot from the installation disc, and the disc is not scratched or dirty, then you have a hardware fault.
Make a "Genius" appointment at an Apple Store to have the machine tested.
Back up all data on the internal drive(s) before you hand over your computer to anyone. If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to bare metal from any of them.) Don’t erase the recovery partition, if present.
*An SSD doesn't need to be zeroed.
There are several ways to back up a Mac that is unable to fully boot. You need an external hard drive to hold the backup data.
1. Boot into Recovery (command-R at startup) or from a local Time Machine backup volume (option key at startup.) Launch Disk Utility and follow the instructions in the support article linked below, under “Instructions for backing up to an external hard disk via Disk Utility.”
How to back up and restore your files
2. If you have access to a working Mac, and both it and the non-working Mac have FireWire or Thunderbolt ports, boot the non-working Mac in target disk mode by holding down the key combination command-T at the startup chime. Connect the two Macs with a FireWire or Thunderbolt cable. The internal drive of the machine running in target mode will mount as an external drive on the other machine. Copy the data to another drive. This technique won't work with USB, Ethernet, Wi-Fi, or Bluetooth.
How to use and troubleshoot FireWire target disk mode
3. If the internal drive of the non-working Mac is user-replaceable, remove it and mount it in an external enclosure or drive dock. Use another Mac to copy the data.