My iMac dont restart!!!!when i push on power stays always a blue screen, have already tryed with all commands conbination and doesnt respond..please!!!!!any idea???

Question

tried also to restart with Leopard CD, finally looked in a good way to solution, where into disk utillity and tried to repair disk and says that disk was OK!!!! inafter that asked me for password and says my password ist not correctm,, i tried to repair permissions and told me to write  the new password... i did it...after that and in the same way i read in many forums but my iMac never more respond.... always blue screen but this time not even de CD comes out... a friend of mine told me to try to restart with Linux... to save my data... have important folders there but ist no possible.... any idea please... i have look all around the net and no solution...
Thanjs...

Answer 1

If you can't find the system discs that came with your computer, use fsck (a command-line utility that may be able to verify and repair a disk)
To use fsck:
1. Start up your computer in single-user mode to reach the command line.
2. At the command-line prompt, type /sbin/fsck -fy
3. Press Return. fsck will go through five "phases" and then return information about your disk's use and fragmentation. Once it finishes, it'll display this message if no issue is found:
** The volume (nameofvolume) appears to be OK
If fsck found issues and has altered, repaired, or fixed anything, it will display this message:
*** FILE SYSTEM WAS MODIFIED ***
Important: If this message appears, repeat the fsck command you typed in step 2 until fsck tells you that your volume appears to be OK (first-pass repairs may uncover additional issues, so this is a normal thing to do).
4. When fsck reports that your volume is OK, type reboot at the prompt and then press Return.