With the hinge free to move, the iMac will be unbalanced and hard to work on. Place an iMac service wedge, in the stand to stabilize the iMac.

If you are using the iFixit cardboard service wedge, follow these assembly directions to put it together.

Before beginning any work on your iMac: Unplug the computer and press and hold the power button for ten seconds to discharge the power supply's capacitors.

Be very careful not to touch the capacitor leads or any exposed solder joints on the back of the power supply. Only handle the board by the edges.