Grey screen at startup (even after I remove all internal hard drives)

[macpokerstars]

Hi there,

My iMac 27" late 2009 doesn't startup anymore. I get stuck on that all-grey screen (before the Apple logo appears). And I think that the loud beeping sound (that Macs make when they start up) is cut out about 80% through. At this stage of the booting, a quick press on the power button immediately turns off the iMac.

I removed all peripherals etc.. (cf all other threads regarding that issue).. zapped the PRAM etc.. Nothing works.

So I decided to open up my iMac and disconnect the SATA cables of the 1Tb hard drive as well as the SSD drive (optical bay instead of the Superdrive).

And even then, the problem persists.

Does that mean that my motherboard is fried? How can I tell if this is the case?

Note: since I had installed Mountain Lion on the SSD, my computer would crash often for no reason (spinning wheel even if I don't do anything) and I would have to dirty-power-off the mac every time (press Power button for 5 seconds)

Thanks in advance

 

[malvicus]

Hi there,

My iMac 27" late 2009 doesn't startup anymore. I get stuck on that all-grey screen (before the Apple logo appears). And I think that the loud beeping sound (that Macs make when they start up) is cut out about 80% through. At this stage of the booting, a quick press on the power button immediately turns off the iMac.

I removed all peripherals etc.. (cf all other threads regarding that issue).. zapped the PRAM etc.. Nothing works.

So I decided to open up my iMac and disconnect the SATA cables of the 1Tb hard drive as well as the SSD drive (optical bay instead of the Superdrive).

And even then, the problem persists.

Does that mean that my motherboard is fried? How can I tell if this is the case?

Note: since I had installed Mountain Lion on the SSD, my computer would crash often for no reason (spinning wheel even if I don't do anything) and I would have to dirty-power-off the mac every time (press Power button for 5 seconds)

Thanks in advance

If you had brought it to an Apple authorized service provider, the first step would have been to run it through Apple's Diagnostic program which would have netbooted your computer and looked at your iMac's hardware. If the hard drive failed the diagnostic, then a hard drive failure would probably describe your problem. The next question would be to ask if you've backed up your data if the diagnostic also revealed no recent Time Machine Backup. Or perhaps your boot sector got corrupted and a format of the HD and reinstallation of the OS would have solved the problem. Getting that information would be free as it's information gathered at the service desk of an authorized service provider. The solution could have involved swapping out the drive or formatting the drive and reinstalling the OS at a cost that is significantly lower than replacing the Logic Board.