Late 2007 27" iMac

So a couple months ago my beloved iMac (my first) booted to a grey screen with a never-ending circle on the screen. It had been running slow and weird ever since upgrading to Lion (lesson learned).

The data was not a problem since I had all files backed up to my 2T NAS. I didn't do anything with it until this past weekend when I took on the task of attempting a rebuild.
I formatted and installed the original OS (Tiger). Once installed, there were updates. Two updates failed. I thought, "no problem", they'll get caught when I upgrade to Leopard. Leopard went in - no problem. Snow Leopard went in no-problem. But on re-boot after Snow Leopard, I was back at the grey screen with the never-ending circle. = (

I did disk-utility which said I had errors. I zero-wrote the drive, then disk-utility said all was well. I started again.

Tiger went in fine. Ran disk utility after Tiger install, no errors. I installed Leopard. This time Leopard install failed. Disk utility reported errors. Formatted drive and then disk utility reports all is well.
Finally, I just installed Tiger and did not do any updates to it.

Sorry to be so long-winded, but - is this indicative of a hard disk failure or something else? I'll replace the HD if that's all it is. Why does disk utility report that all is well, when it may not be?

Why didn't you just reformat and install Snow leopard

There is no need to start with tiger

brooksmf224 said:

Sorry to be so long-winded, but - is this indicative of a hard disk failure or something else? I'll replace the HD if that's all it is. Why does disk utility report that all is well, when it may not be?

Click to expand...

You have been describing one way in which a hard drive can fail. Disk Utility often reports
a failed or failing drive as good. It only performs basic tests, your drive failed as you wrote extensively to it, Disk Utility does not read and write to every sector, so will not identify every way in which a drive can fail.

louishen said:

Why didn't you just reformat and install Snow leopard

There is no need to start with tiger

Click to expand...

Sorry, I think I did start with just Snow Leopard, but the process halted at some point saying there was a problem and I believe I had a "restart" button. After that, disk utility reported an error - then I ran the zero-write, then disk utility reports "all OK". That's when I started with Tiger-->Leopard-->Snow Leopard.

Trash that drive and get a new one. You'll be fooling with it for hours on end only to finally have it completely crash and not be recognized. Save yourself aggravation and get a new drive and then install Snow Leopard. Afterward, restore your data from the backup.

^^^^ Agreed with chscag. Once a drive starts these type of problems, you end up just spending countless wasted hours. Can't tell you how many times I've gone through that type of thing. No more... Drives are too cheap.

(And the upgrade to Lion would not be the cause - only coincidental.)

Update: Installed new HDD. Snow Leopard went in - no problem - did the Lion upgrade, Parallels VM with Office 10 Ultimate, Aperture, etc., etc. Works like a dream! Thanks!