Help! Unable to erase hard drive using Disk Utility

[GSMiller]

I recently purchased a new PC and want to trade in my Intel Core 2 Duo iMac. I'm uneasy about sending it in without first completely wiping the hard drive but I am having a bit of an issue.

For the last few months my iMac has been running extremely slow. I see the rainbow wheel of death more often than I see the mouse pointer. After replacing the RAM the problem still remained so I am pretty sure my HDD is failing.

The only way I know how to erase the HDD is to boot from the Mac OS X Snow Leopard disc and use Disk Utility from there. However, when it brings up the list of disks, all it shows is my SuperDrive and the Snow Leopard installation DVD. It doesn't have C:/ drive or Macintosh HD isn't listed anywhere. It does the same thing if I simply try reinstalling Snow Leopard.

Please help

 

[rj86]

So you don't see something like this (attached screen)?

 

[GSMiller]

So you don't see something like this (attached screen)?

Right, the only thing listed in that pane is my Pioneer optical drive with the installation disc underneath.

 

[rj86]

Weird... Definitely a hardware issue with the drive itself.

Did you say you can still boot to the internal disk? Back up any data while you still can and take it to an Apple store/authorised service provider to get it fixed.

 

[GSMiller]

Thankfully I have been able to back up all of my documents to my external drive. I really don't want to have to spend the money to get it fixed as I have already bought a new PC and was going to recycle my iMac through Gazelle. I was just hoping to erase all of my personal data still floating around the HDD.

 

[MacHamster68]

as the HDD is failing anyway very soon just get a normal 250gb HDD and replace your one , sorted ,dump your broken disk sell the iMac , if you want to sell it you want the buyer to pay money and you get more for it with a working HDD anyway, otherwise you need to sell it as spares or repair which brings you $100 and i guess you want a bit more for it or?
changing the HDD isnt that tricky to do if you are a bit careful, lots of how to's online with nice pictures

 

[rj86]

The only way to guarantee data security is taking the HDD out and smashing it to pieces Even then the FBI could probably find something.

It is very strange that you are unable to see the HDD in Disk Utility while still being able to boot from it. It indicates a connection problem where something has been shaken slightly loose or a faulty disk drive. Depending on how brave/confident you are with a toolkit, you could open up the machine with instructions found on the web and replace the HDD yourself. Again, that would guarantee nobody would be able to steal your information.

 

[seniorgeek]

Download disk shedder for windows, burn a cd, boot from it, run it and wipe the drive, this is assuming you have Windows installed on the Mac.

It may be available for the Mac also.

 

[GSMiller]

I agree it is acting very strange. I was even able to delete my Windows XP partition.

I have strongly considered replacing it myself but after reading tutorials and watching a video on YouTube it seems a little intimidating. There is a computer repair shop in town that will replace iPhone screens so I may give them a call. There is an iMac comparable to mine going for nearly $500 on eBay right now

 

[rj86]

Well the options are laid out for you just a case of making the decision.

Good luck whatever you choose.

 

[Gramp]

I recently experienced the same symptom with a 4-year old Core 2 Duo.

I think this clearly indicates that the problem with the HD is something more than bad sectors or the platter itself.
More like the HD logic board, the spindle motor or the head mechanism.
Could be an intermittent - but sounds like you have tried many times after power downs etc.

I gave up and just replaced the HD - it's fairly easy in a pre-aluminum iMac.
Not fiddly like it is with the alum. cased ones where the glass has to be pulled off, and lots of sticky foil has to be lifted up and replaced.

You just need a T7 and T8 screwdriver with a long thin shaft, and a small Phillips. And about an hour of your time - maybe less.

It will likely be a Western Digital Caviar SE HD in there - so as you are selling anyways, just try and find a good used one.
Around here, good used WD's go for about $30 - $40 for a 500GB or 1 TB, or even $20 if you can find a 250GB one.

A Caviar Black would cost more, but I think all you need to do is get the machine back to original spec. or slightly better.

With SL installed, original box, clean keyboard, and all ready for a new user to configure, $500 is a reasonable target price.

Just bad luck that your HD failed within 5 years - others could last twice that or more, some could fail within the warranty period (but not too likely).

 

[GSMiller]

Thanks for all the help and great responses.

Gramp, you being able to successfully replace your HDD makes me hopeful. I've replaced the hard drive in a white MacBook but having to take out the iMac screen has just seemed too difficult. This is only about the third computer I've owned that has had a hard drive fail (the other 2 were HP's). Of course my 3 year AppleCare warranty ended last October. What a waste of money that was.

 

[Gramp]

..... but having to take out the iMac screen has just seemed too difficult.

On your iMac model, assuming it is the white plastic case one, not alum.,
you just push in the RAM retainer levers so that the back of the case (or bezel) can be eased free,
then you can lay the back flat on the worktable without even disconnecting the iSight wire.
I used the iFixit directions - they do disconnect wires but that is not necessary.

Probably easier than what you did on the Macbook - more working space anyway.

I intend to always stay with these pre-mid 2007 iMacs just because they are still easy to fix.
Processor speed is not a big deal for me, but I suppose there will be other things like USB 3 that I will thirst after.