Intel I-Mac Will not boot from hard drive or CD-ROM

I was wondering if anyone knew which forum I should go to for help with an Intel I-Mac. It will not boot from The CD-ROM or hard drive without locking up? I have already tried a ton of stuff that I will post when I get to the right forum.
I've been browsing around just a little, and haven't found any post with similar problems. Thanks

I have the same problem!! need help if anyone knows... black screen of death from hdd or cd rom

When does it lock up?

You can't boot into OS X?

We need more info. Why are you trying to boot from the DVD drive?

My problem started after installing Apple Bootcamp and Windows Vista. I tried everything but all I would get was lockups stating Must power down or restart computer. I was able to boot into single user mode by holding Command S during sartup. This deleted my Windows volume making my computer bootable. I have no idea why a bad volume caused my I-Mac to hang while trying to boot a CD.

The below command line is what fixed my problem. If you have not installed Apple boot cam and any version of Windows, this may not be your fix. I am only mentioning this because I was unable to use my out of warranty Mac for three months which forced me to learn some cool tricks, and some stuff about linux.

/sbin/fsck -fy
/sbin/mount -uw /

Watch the spaces and then issue a "reboot" at the prompt.

1. If I hold the C button while booting to boot from CD-ROM I get a panic alert.(panic alert meaning lockup, I have to restart or press and hold power button)
2. Holding down D button upon startup will run Apple Hardware test just fine, but no errors found.
3. I can press Option-Command-P-R to reset NVRAM successfully.
4. I can press Option during startup to start the Startup Manager. I can see my Macintosh Hard Drive and CD-ROM, but get a panic alert if I click on either icon. I’m not sure what happened with the Windows Vista hard drive Icon.
5. I can press N during startup to start up from a compatible network server. I see a flashing globe and then a panic alert. Not sure what this function is for.
6. If I press T during startup for Start up in FireWire Target Disk mode, I get a weird symbol that looks like a Y floating around the screen. I have no idea what target disk mode means.
7. If I press Shift during startup to boot in Safe Boot mode, I get a panic alert.
8. If I press Command V during startup for Verbose mode, it appears that I am at a Unix style Command Prompt that hangs.
9. If I press Command S during startup for Single-User mode, I am at the Unix Command prompt which works, but I do not know any commands except fsck –fy which I guess is like a DOS CHKDSK command that tells me my Volume appears OK.
10. Pressing Option-N during startup to start from a NetBoot server using the default boot image gives me the flashing globe icon again, and then hangs.
11. I tried resetting the System Management Unit thanks to the Unix forum guys, but still have the same problems.
12. My next step is to find a Mac friend to burn the Firmware Restoration CD file I downloaded thanks to Michael from the Unix forum. If that does not work I will try whatever you ask.
13. I can boot my I-Mac using a Linux Live CD called Slax and surf the net and play with the software. It runs just great; I just don’t think this 200MB version has the capabilities to format the hard drive or Install to hard disk like Fedora Live does. By the way, the Fedora Live version of Linux hangs after booting from the CD. It boots just fine on my PC.

I still haven't tried to boot into Target Disk mode using another MAC. I have to but a firewire cable first, if that doesn't work, I will have to buy Diskwarrior and give it a shot.