iMac Intel 21.5" EMC 2308 CPU Replacement

Loosen the three Phillips screws securing the access door to the bottom edge of your iMac.

Remove the access door from your iMac.

Stick a suction cup near each of the two top corners of the glass panel.

If your suction cups refuse to stick, try cleaning both the glass panel and the suction cup with a mild solvent.

Gently lift the glass panel perpendicular to the face of the LCD enough to clear the steel mounting pins attached along the underside of the top edge of the glass panel.

Pull the glass panel away from the lower edge of the iMac and carefully set it aside.

Remove the eight 8 mm T10 Torx screws securing the display to the outer case.

Slightly lift the top edge of the display out of the outer case.

Pull the vertical sync ribbon cable out of its socket on the LED driver board near the top left corner of your iMac.

Rotate the display out of the outer case enough to disconnect the LED backlight power cable from the LED driver board.

Squeeze the two display data cable connector arms together to unlock it from its socket on the logic board.

Pull the display data cable connector away from its socket on the logic board.

Disconnect the LCD thermal sensor cable connector from its socket on the logic board.

Carefully pull the display toward the top edge of your iMac and lift it out of the outer case, minding any cables that may get caught.

Remove the following four screws securing the power supply to the outer case:

Two 22.2 mm fine-thread T10 Torx

One 25 mm coarse-thread T10 Torx

One 9 mm coarse-thread T10 Torx

Carefully lift the power supply out of the outer case and rotate it to expose the cable lock as shown, minding the DC-Out cable still attaching it to the iMac.

Disconnect the DC-In cable by depressing the locking mechanism on the connector while you pull the connector away from its socket on the power supply.

Once the locking mechanism has cleared the socket, pull the DC-In connector away from the power supply.

Disconnect the AC-In cable by depressing the locking mechanism while pulling the connector away from its socket.

Remove the power supply from the outer case.

Pull the optical drive thermal sensor connector straight away from its socket on the logic board.

Remove the four 9 mm T10 Torx screws securing the optical drive to the outer case.

Lift the inner edge of the optical drive and maneuver its connector past the frame attached to the logic board.

Carefully pull the optical drive off its mounting pins on the edge of the outer case to gain clearance for disconnecting the optical drive cable.

Use the flat end of a spudger to help disconnect the optical drive cable.

Remove the single 13 mm T10 Torx screw securing the optical drive fan to the outer case.

Pull the optical drive off the pins attached to the outer case.

Pull the optical drive fan connector away from its socket on the logic board.

Remove the optical drive fan from the iMac.

Pull the left and right speaker connectors toward the right side of the iMac to disconnect them from the logic board.

Disconnect the audio port cable by pulling its connector toward the right side of the iMac.

Disconnect the AirPort cable by lifting its connector off the socket on the logic board.

Disconnect the following cables by pulling their connectors toward the top edge of the iMac:

Camera cable

Hard drive thermal sensor

Hard drive fan

Microphone

Disconnect the following cables by pulling their connectors toward the right edge of the iMac:

Ambient temperature sensor

Bluetooth cable

Disconnect the CPU fan and power button by pulling their connectors toward the left edge of the iMac.

If present, remove the piece of tape covering the IR sensor connector.

Disconnect the IR sensor by pulling its connector toward the top edge of the iMac.

Use your fingers to lift IR sensor assembly straight up out of the outer case.

Remove the following six screws securing the logic board to the outer case:

Three 25 mm T10 Torx

Two 21.5 mm T10 Torx

One 7 mm T10 Torx

Remove the plastic ducts from the side of the LED driver board and the hard drive by pulling them away from the outer case.

Carefully remove the aluminum tape attaching the GPU heat sink to the outer case.

Carefully pull the logic board slightly away from the outer case.

While holding the board away from the outer case, rotate the board back and forth while lifting up to release it from the outer case.

Now that the lower edge of the board is free from the outer case, rotate the logic board toward yourself to expose its rear face.

Carefully pull the optical drive connector away from its socket on the logic board.

Disconnect the DC-In cable from the logic board by simultaneously depressing the locking lever on the connector while pulling it away from its socket.

Remove the logic board from the outer case.

Use a pair of tweezers to lift the heat sink thermal sensor connector straight up out of its socket on the logic board.

Remove the following six screws securing the heat sink to the logic board:

Five 6.5 mm T8 Torx

One 7 mm T10 Torx

Lift the heat sink bracket off the logic board.

Carefully lift the logic board off the heat sink.

Carefully pull the CPU retaining bar away from the CPU socket.

Rotate the bar toward the center of the logic board.

Rotate the CPU clamp away from the CPU.

Carefully lift the CPU straight up off its socket.