One of my tasks set by my directors last week was to replace a hard drive in a computer, I’d already replaced hard drives in PCs and Laptops previously so thought nothing of it. Jim then told me it was an iMac and that the hard drive was located behind the screen.

Over the past year I have had to replace hard drives in computers/servers and laptops but never an iMac. I’d heard that replacing a hard drive in an iMac was quite difficult due to the reason that an iMac doesn’t have a tower, the hard drive is located behind the screen.

The client had previously taken the iMac to the Apple store and was quoted over £500 for this work to be carried out, they phoned us and we said we would take a look but couldn’t promise anything.

I had a look online at some guides/tutorials on how to replace an iMac hard drive and what I would need to complete the job.

I had a good read through the guide to get familiar with the process of the hard drive replacement, had a look what tools I needed to use to remove the glass, screws and to remove the hard drive. I had the majority of the tools in the office but had to order in suction cups as this was used to remove the glass to gain access behind the display to locate the hard drive.

Tools I needed to complete the hard drive replacement:

  • Two heavy duty suction cups
  • Phillips Screwdriver
  • T6 Torx Screwdriver
  • T8 Torx Screwdriver
  • Working replacement Hard Drive

As soon as the suction cups arrived I was ready to start replacing the hard drive.

The first stage was to remove the Access Door, to do this you have to use a Phillips screwdriver and locate the screw which is under the iMac. After unscrewing the screw I then could remove the access door.

Access Door

Stage 2 was to remove the glass panel, the glass is fixed into the front bezel using magnets, this is where the suction cups need to be used to lift the glass from the iMac. I had to gently lift the glass from the iMac and place the glass in a safe place.

Suction Cups

Stage 3 was to remove the 12 screws securing the front bezel to the rear case, two types of screws are used to hold the front bezel to the rear case. This consists of eight 13mm T8 Torx screws & four 25mm T8 Torx screws.

Removal of the front bezel

When the screws are removed be careful not to lift it off without removing the microphone cable which is still connected to the iMac. Disconnect the microphone cable connector and remove the tape.

 iMac with front bezel removed 

Front bezel removed

Now that the front bezel is removed the LCD temperature sensor needs to be removed from its socket on the logic board. This may need to be taken from behind the logic board.

LCD Temperature Sensor

Remove two of the 5.3mm T6 Torx screws securing the data display cable to the logic board. Use the black tab to pull the data display cable from the logic board. (Bottom centre of image)

Removal of screws securing the data display cable

Now the screws securing the display panel to the rear case can be removed using a T8 Torx screw, these screws are 12mm in length.

Display panel to rear case

When the screws have been removed you can lift the left edge and rotate it towards the right edge of the iMac. When the iMac is tilted you can see four cables these can be either disconnected or if you have somebody close by you can ask them to prop up the display panel as you should still be able to reach around to disconnect the hard drive.

Tilted screen HD

As you can see the Hard Drive has been located, before lifting the hard drive out of the iMac you will need to remove the pieces of tape securing the hard drive thermal sensor cable from your iMac. Now you can disconnect the hard drive thermal sensor by pulling its connector toward the top of your iMac. In the image above you can see the hard drive bracket you need to press the top of this down to release it from the rear case. When the hard drive is released you can then remove the SATA cables & power cables from the hard drive.

The hard drive will have foam tape covering the hard drive this connects the thermal sensor, this also needs to be removed.

Now the hard drive has been disconnected you can lift the hard drive out of the iMac and remove the two T8 Torx screws securing the hard drive bracket to the hard drive.

Hard Drive

Locate your new hard drive and reassemble the screws so it is placed back in the bracket.

When the new hard drive has replaced the old hard drive it can be placed back in the iMac and the SATA cable, power cable and hard drive thermal sensor can be connected to it.

Now its time to start putting it back together, I started off by lifting the display panel back onto the iMac and screwing the eight 12mm T8 Torx screws back on so the display panel was held back in place.

Display Unit in place

Now the display unit is in place I could attach the data display connector back to the logic board, screw the two 5.3mm T6 Torx screws back in which would then secure the data display cable to the logic board.

Last stage was then to place the LCD temperature sensor connector back into the socket on the logic board.

Before re attaching the front bezel to the iMac I decided to make sure that the hard drive was recognised by the iMac. I then had to install Mac OS onto the hard drive by using a Snow Leopard  installation disk.

Apple Logo

I had to use disk utility to format the new hard drive to be used with a Mac OS. The hard drive was formatted to Mac OS Extended (Journaled)

Disk Utility

After the hard drive was formatted the installation could begin:


Now I knew that the installation was successful I could then re attach the front bezel to the iMac. Make sure to re attach the microphone cable. Now the front bezel is re attached the 12 screws (Eight 13mm & Four 25mm T8 Torx screws) securing it to the rear case can be screwed back in.

Front Bezel

After the screws are screwed back in so the front bezel is attached to the iMac the glass can then be replaced.

Suction Cups

Last step is to replace the access door to the iMac

Access Door

iMac replacement hard drive successful


iMac in working order, hard drive install is a success.

A few checks on the iMac to make sure everything was working as it should be and it was ready to be handed back to the client.

We charged less than half the price that Apple charged to replace the hard drive and the iMac was as good as new.

Thanks to ifixit for the detailed guide.