please help imac grey screen

firstly I would like to thank any answers that people may give.
I have a 2008/9 20 inch imac that is stuck on a grey screen ( no apple logo)
my wife informed while I was at work that the imac was making a noise , abit like when a key is stuck down, so she shut the imac down in the proper manor.
when I started the mac it came up with a grey screen and then proceeded to load windows 7 on boot camp.
I have tried the following
1. holding down the c key at start up-- key,,,result..doesn't read the disc
2. tried to reset pram-- result... no difference
3.command key and r...result ..no difference
4. tried to boot in safe mode....result ..no safe boot
it is as if it doesn't recongise anything mac related,, I live 30 miles away from nearest apple shop ,,and was hoping someone could save me a journey. from reading I belive that the only way to access imac is by connecting a MacBook by firewire ?
any help would be gratefully excepted. thanks dave

davemill said:

1. holding down the c key at start up-- key,,,result..doesn't read the disc

Click to expand...

When you did this...did you have a bootable CD or DVD disc in the optical drive?

- Nick

pigoo3 said:

When you did this...did you have a bootable CD or DVD disc in the optical drive?

- Nick

Click to expand...

I tried the snow leopard install disc which was an upgrade ,,also the 2 original install discs that came with computer..but to no avail.

If you hold down the OPTION key right after the Startup Sound, and keep it down, a boot menu should pop up. What do you see there? Just the Windows partition? If so sounds like the hard drive bit the dust.

dtravis7 said:

If you hold down the OPTION key right after the Startup Sound, and keep it down, a boot menu should pop up. What do you see there? Just the Windows partition? If so sounds like the hard drive bit the dust.

Click to expand...

tried that,,nothing,,but in ****** windows I used a program on it and it showed mac partion there,,but could not access it...only had this hard drive fitted 2 years ago by apple under apple care extra cover,,,which as now run out..thanks

davemill said:

I tried the snow leopard install disc which was an upgrade ,,also the 2 original install discs that came with computer..but to no avail.

Click to expand...

If that Snow Leopard disk is an "upgrade" disk...it may not be bootable (this disk will say "upgrade" on it). This is different from a retail full install disk. The upgrade disk needs to see OS 10.5 on your HD before working.

These gray disks that came with the computer should work (as long as they are the two actual disks that came with the computer...and not from somewhere else). If this is the case:

- the optical drive may be dirty (blow some canned air in there)
- the disks may be dirty
- or both

If after trying everything I mentioned does not work...you optical drive may be a goner.

And if you cannot boot from your HD...it may be a goner as well.

- Nick

davemill said:

tried that,,nothing,,but in ****** windows I used a program on it and it showed mac partion there,,but could not access it...only had this hard drive fitted 2 years ago by apple under apple care extra cover,,,which as now run out..thanks

Click to expand...

no boot menu pops up...just bypasses and goes straight to windows.

Remember I am just guessing about the hard drive but it sure seems like something went south and the hard drive is the first thing I would check.

It's interesting though that Windows on the same drive works.

Yes...if Windows is working...then the HD is probably fine. Then the Mac OS X partition:

- May have gotten corrupted.
- Important files may have been deleted or misplaced.
- The Mac OS X partition may be full.

Compounding this is a posssible dead optical drive...and we have a big headache!

* Nick

Nick, seen part of the drive mess up before with damage just to the one partition. The 320 WD that came in this iMac was that way. The first and largest partition was at the time Lion and the smaller one SL. SL was fine but Lion kept corrupting. Did a check on the drive and there was damage in the area where the 1st partition resided. Even a fresh install would be slow and mess up completely in a hour of use. New drive and it's been working since. I had full Time Machine backups of Both partitions so I lost nothing.

okay lads ,,thanks for all replies,,,don't think optical drive is k-put becos it reads discs normaly,just doesn't want anything to do with mac software,,also tried a plug in dvd drive,,same problem.
looks like a trip to apple store !!!!