Grey Screen at Boot

Greetings,

I've got a Macbook (not pro) that's only showing a grey screen when booting. I tried resetting the PRAM and NVRAM and using the Disk Utility (on the OSX DVD). But the Disk Utility gives an error "invalid sibling link" and won't complete.

Google results suggest going to Single User mode and trying "fsck_hfs -r /dev/disk0s2" but the system won't recognize the CMD+S combination.

Can I use Fsck from the terminal that's on the OSX DVD instead?

Thanks,

ZS

When you do command/s you need to hold it down until a screen of text appears in front of you, then you type the "fsck -fy" command and press enter, repeating until it says" the macintosh HD appears to be ok" then type reboot and hit return.
FSCK should definitely fix this unless the HD is dead.

My main problem with CMD/S is that it's not working -- at all. I held it down while pressing power, tried after power but before the grey, during the tone, during the grey... none of them work.

How long does it take for the text to appear?

Around a minute. Switch it off completely, hold down the Apple and S keys together, keep them held down and switch it on. Keep holding and the random looking text will appear. You cam then release and when the text has loaded, continue with the FSCK command.

No dice. I followed your instructions precisely, but the grey screen persists... At about 5 minutes an icon of a question mark inside of a folder appears.

Ok, that will generally mean that your HD is dead I'm afraid, though you could try a clean install, as it may be an OS failure (unlikely).
Do you have access to another Mac at all? You could try booting in target disk mode if so, just to see if it can be repaired from there.
Of course, if your Mac is less than a year old it's under warranty, if not then a new HD is the only option.
Sorry if that's bad news.

I suspect you're right about the hard drive... I gave targeted disk mode and got an error "Invalid B-Tree Node Size."

I'm now wondering if there's anything that can repair the disk... The Mac is my wife's, and has no essential data on it... But I'd rather avoid shelling out the money to buy a new drive now.

Have you tried repairing the drive in Target disk mode?

Yeah. That's how I found the B-Tree error

Right, but it won't let you repair?
Norton Utilities used to be able to fix this kind of error, and it's an OS error, so Diskwarrior may well be able to.
To be honest, I'd try a clean install, because you may find it's fine afterward.

Disk Utility, Diskwarrior, and Drive Genius all failed to repair the drive.

OS X's install disc doesn't even show the drive -- and therefore means I can't select the disk onto which the system needs to be installed.

Ok, then a new drive it is I'm afraid. Not too expensive these days, but a pain nonetheless.

So I got the new hard drive and installed it. But the Macbook continues to boot without any iconography on the grey screen, and the OSX disc continues to show no hard drive options when I try to install.

I can see the new drive vis Disk Utility in Targeted Disk mode, however, and am formatting it now.

You should be fine once formatted correctly.