Soon after purchasing a 24” iMac, the need to tweak and upgrade hit me so I decided to upgrade the stock 320gb hard drive to a larger and faster drive. While the procedure is not for the faint of heart, it certainly is nothing to be too worried about doing if you are comfortable with taking apart electronics. No small animals or Apple warranties were hurt in this procedure, but as always it’s a ‘proceed as your own risk’ endeavor. I originally posted this how-to on a popular Mac enthusiast web site, MacRumors where it has proven to be very helpful to many users. Though this isn’t directly about the Mac Pro, I thought having it here as I build my library of tech articles and tidbits might prove to be useful to some.
The beginning: 24" iMac with stock/entry level 320 gb HD. Stock drive is an 8mb western digital WD3200AAJS. The only tools needed will be a set of TORX drivers/bits. Make sure you have sizes T4, T6 and T8.
First off, taking out the glass is trivial... it's LIGHT and takes very little force. I used two (could have made it with 1) suction cups with hooks to let you hang stuff on glass with. Side note: One of my concerns in doing this upgrade was introducing dust between the LCD and glass. I avoided this by using a can of compressed air and gently blowing off any dust on the LCD and inside of glass before reinstalling the glass.
Glass pulled out: notice LCD itself is glossy:
Next remove the memory slot cover on the bottom held on by two phillips head screws. These can be pretty tight, they were on mine so make sure you have a driver that fits the head snugly to avoid stripping the screws. After that, simply unscrew all the screws along the edge (under the glass). There are 12 screws, 3 different lengths. Just pay attention to where they came from, but truly they only fit in the right holes (pick one too short, it'll be obvious, etc)
Inside of Face - Notice the magnets:
iSight camera - cable with inline plug... easily unplugs:
Now the only part that is slightly tedious - The LCD removal. The LCD is attached with 8 Torx screws. There are three cables that connect the LCD to the computer. While you could just disconnect 2, I think it is worth just unplugging all three and removing the LCD to make working in the unit easier. One plug (DVI) is actually screwed in, very small torx... Watch the SMALL screws:
Second connector - 4 wires... lower left, easily unplugged (plug on the right):
Worst connector of the three - Power to the LCD. It is a bit tight fitting, much worse getting back in than out. You can do this one of two ways: Either unplug the connector from the power inverter board or peal back the sticky tape on the LCD itself and unplug the cable from the LCD. The 2nd way is probably easier, but perhaps messier. I chose to unplug the plug from the inverter. It does take some patience to plug it back in, just take your time.
Stock Drive... interesting thing, the pad with the wire going into it. This is a thermister for the temperature monitoring chips/system in the iMac. Not a big deal, just have to transfer the mount to the new drive.
To remove the HD, 2 bolts (torx) must be removed, the other two mounting holes on the HD are posts that are removed after the drive is out. The clip for the thermister peels right off
Hard drive out. Note the posts, they are just screws with no heads, taken out with a torx.
Hard drive out.... For those with the resources, perhaps you’ll be placing a nice fast SSD in that empty spot?
Attaching Thermistor back to the new drive and then mounting it back into place:
From here, just connect the power and SATA connectors to the new drive and reverse the rest of the procedure to arrive back at a fully functioning and nicely upgraded iMac:
The Result: A significantly faster iMac for a minimal amount of time and money.