2007 iMac won't boot

[SgtPepper23]

My 2007 iMac won't boot past the grey screen, not even with the Apple logo in the centre of the screen. I've tried booting into the Boot Manager, tried using the recovery partition, tried booting from an external USB and FireWire drive, reset the NVRAM, reset the SMC, tried booting with a DIskWarrior boot disk (can't even eject the disk now... i've tried holding onto the mouse to force eject), changed the RAM back to the original...

Anyone else have any suggestions? I can't really figure it out and i need this machine up and running. I appreciate the help!

 

[ChanneledDan]

Since it's quite old I would guess the hard drive has died perhaps? The recovery partition would be on there two since there's only one internal drive. Have you ever had it replaced or is it still the original drive? What happenes when you try booting from recovery partition or something else, it just stays at a grey screen?

Also, if you mean it won't eject a CD, did you try holding down the 'eject' button on the keyboard while the computer (attempts to) power up? You might have to hold it for like 60 seconds or more.

 

[Willis]

When you hold the option key to get the startup manager, are you able to see available boot drives and select them?

If it isn't booting to a known good OS on an external drive, then it sounds like you have a GPU failure.

As you Mac is vintage, it can't be repaired in an Apple Store so you'll need to go down another route to get it repaired. If you have a backup of your computer, I'd suggest investing in a new machine, especially if its a GPU failure. If its a machine with integrated graphics, then it's an MLB replacement.

 

[SgtPepper23]

Ah bummer... thanks for the advice, everyone.