iMac 24″ Opened and Upgraded

A Fairfax, Virginia customer recently had an iMac 24″ Intel Core 2 Duo 2.16 GHz (the two year old white acrylic plastic model) that had a malfunctioning video card (random lines, ghost windows, static). Otherwise it worked great, so we decided to fix it.

Bad Video Card

Because the iMac was not under AppleCare warranty, we decided not to have Apple fix it for what would probably be $700-$1000.

I ordered a new NVIDIA GeForce 7600 GT video card. The GeForce video card for this iMac has a special MXM PCI Express connector. So you can’t just pick up any GeForce 7600 GT or 7300 GT. Only WeLoveMacs.com appears to sell the correct video card.

Screws Galore

The iMac has lots of philips and hex screws of different sizes. I used these baggies and labels so that I could reassemble the iMac. I do the same thing when taking apart a laptop.

Hard Drive Upgrade

While I had the iMac opened, we upgraded from a 500GB to a 1TB hard drive. This required prying off the hard drive’s heat sensor and reapplying it to the new drive with rubber cement.

Not an Easy Job

The video card unfortunately is underneath the motherboard, which Apple refers to as the “logic board”. It is much easier to bring an iMac or MacBook to Apple for repair than attempting it yourself. Even if you are somewhat skilled, the process takes hours. But if you have an out-of-warranty computer, this could save you some money.

Because there are no other photos of the internals of this iMac online, I’m posting a bunch here:

Erasing Your Hard Drive with Apple’s Disk Utility

If you attach a hard drive to a Mac OS X computer, you can erase it using the built-in Disk Utility.

The cheapest way to attach an external drive is with an adapter such as this one for IDE hard drives from Newegg for about $18.

Once connected on a Mac OS X computer, click Go – Utilites – Disk Utility. From there, click on the disk you want to erase, click the Erase tab at the top, then click Security Options. This will give you the following options:

Zeroing out the data will erase it. For added security, choose the 7-Pass or 35-Pass options to overwrite the data in multiple passes. Like Darik’s Boot and Nuke utility, this will ensure that the data can not be recovered even if someone is using special forensic recovery software.

Once you choose the option you want, click Erase. That’s it.

Truly Erasing Your Hard Drive

Deleting is not Erasing

Most people delete their important computer files before they throw away their computer or donate it to charity. The problem is that file deletion does not overwrite files. Deletion just removes the operating system’s link to that data. Until the files are overwritten, they can still be recovered. This could give someone your valuable bank and credit card information from your web browser cache. It could give someone enough information to commit identity fraud.

While you could physically destroy the hard drive, there are software tools that will securely erase the hard drive so that there is no chance of reconstructing the original data. Software tools are even accepted by the US Government for most deletions of sensitive data.

Darik’s Book and Nuke

My favorite tool is Darik’s Book and Nuke disk. This is a free tool that boots your computer into Linux and then overwrites your drive in multiple passes. Depending on the level of erasure you choose and the speed and size of your hard drive, the deletion can take minutes to a couple of days.

You need to follow instructions to create the CD or DVD yourself from the iso file you download. Then you need to make sure the computer will boot from the CD drive, which could include going into the starting setup (BIOS) to make sure that the CD is first in the boot order. Then just put in the CD and follow the easy instructions.

Once you have Darik’s Book and Nuke disk, you can truly erase your hard drive and keep your information secure.