Loosen the single Phillips screw in the center of the access door.

This screw is captive in the access door.

Remove the access door from your iMac.

The glass panel is fixed onto the front bezel with fourteen magnets around its perimeter.

Stick two suction cups to opposing corners of the glass panel.

To attach the suction cups we sell, first position the suction cup with the movable handle parallel to the face of the glass panel. While lightly holding the suction cup against the glass, raise the movable handle until it is parallel with the other handle.

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

Gently pull the glass panel straight up off the iMac.

The glass panel has several positioning pins around its perimeter. To avoid shearing these pins off the glass panel, be sure to only pull straight up during removal.

Be meticulous about cleaning the LCD and the inside face of the glass panel before reinstallation, as any fingerprints or dust trapped inside will be annoyingly visible when the display is on.

Remove the following 12 screws securing the front bezel to the rear case:

• Eight 13 mm T8 Torx.
• Four 25 mm T8 Torx.

The front bezel is still attached to the iMac by the microphone cable.

Gently lift the front bezel from its top edge off the rear case. It helps to use your thumbs to push down very gently on the corners of the display.

Once the top edge of the front bezel has cleared the rear case, rotate the front bezel toward the stand and lift it off the rear case.

When reinstalling the front bezel, start at the lower edge and make sure it is flush with the rear case before lowering the top edge onto the iMac.

Disconnect the microphone cable connector, removing tape as necessary.

For the front bezel to sit properly, be sure to tuck the microphone cable and connector into the void next to the camera board.

Pull the LCD temperature sensor connector straight up out of its socket on the logic board.

If necessary, de-route the LCD temperature sensor cable from behind the logic board.

Remove the two 5.3 mm T6 Torx screws securing the data display cable to the logic board.

Use the attached black tab to pull the data display cable connector away from the logic board.

Remove the eight 12 mm T8 Torx screws securing the display panel to the rear case.

Lift the display panel from its left edge and rotate it toward the right edge of the iMac.

With the display panel still lifted, disconnect the four inverter cables.

During reinstallation, place the four inverter cable connectors in voids between components attached to the rear panel so the display panel will sit flush.

During reassembly, the order of the inverter cables is interchangeable within each socket.

The rest of this procedure should be done in the cleanest possible work environment to avoid dust getting BEHIND the LCD (I learned this the HARD way!)

Once the LCD panel is removed you need to peel back the black foil from the top edge of the LCD to reveal the clear plastic PCB protector.

Now gently peel the clear plastic PCB protector off the top edge. Make sure you don't damage the flex cables attached to the PBC you are exposing.

There are a total of 8 flex cables along the top edge

Use a sharpie or similar, mark the side brackets on either side of the LCD panel before removing screws as they are different

Use a T10 Torx driver to remove the 2 screws from each side bracket (total 4 screws)

Stand the LCD panel on its TOP edge and locate the lock tabs along the BOTTOM edge. There are 5 along the length of the bottom edge

Use a flat blade driver or metal spudger to Gently pop the bezel off the lock tabs.

Locate the lock tabs on either side of the LCD panel. There are 2 on each side

Use a flat blade driver or metal spudger to Gently pop the bezel off the side lock tabs.

Now gently separate the metal bezel from the main body of the LCD panel

Lay the LCD panel down on with viewing side UP and remove the metal bezel

Make sure you are careful when removing the bezel from the TOP edge as you will be exposing the 8 flex cables mentioned in step 1.

Note the 3 flex tabs on the left edge

Do not damage any of the tabs or flex cables as these are the Row and Column Drivers. Damage to these will will cause faults like vertical/horizontal lines or white screen etc.

WARNING - Once the bezel is removed the LCD is LOOSE in the black plastic frame - only held in by the small gasket underneath.

Using a plastic spudger or pry tool, work GENTLY around the edges of the LCD to loosen it from the gasket below - use GREAT CARE so you don't crack or chip the panel as it is only a couple mm thick

Once the LCD is loose you need to HOLD it in place in the black plastic frame and GENTLY flip the entire assembly so the LCD is flat on the work surface

Remove the tape securing the LVDS cable

Press IN the 2 silver spring loaded catches on either side to release the cable and gently extract it from the connector

Peel the back Black foil and clear plastic PCB protector to fully expose the PCB that runs across the top of the LCD assembly

Remove the 2ea Philips head screws from each end of the PCB

The PCB actually has a 3rd screw hole in the centre of the board. Perhaps my assembly is missing a screw

Gently flip the PCB over 180deg so it is off the aluminum back panel.

Be CAREFUL not to damage the 8 flex cables

The PCB may be attached to the aluminium by some adhesive near the LVDS connector. IF so use a plastic pry tool or spudger to GENTLY lift the PCB up

Now lift the the back panel off the LCD separating the LCD from the back light assembly

Disassembling the back-light assembly is a little fiddly as there are a number of parts that all want to come apart at the same time

Remove the 6 Philips screws from the rear of the back light assembly

Removing the white tape from the CCFL cable.

Un-clip the CCFL cable from the black plastic surround

There are 2 CCFL cables and the process is essentially the same for each

Separate the black plastic surround from the aluminum back plate to access the CCFL tube assemblies

Start by un-clipping the tabs along the top edge of the assembly. There are 4 tabs along the top

The top CCFL tube can be seen and CAREFULLY removed

The bottom of the black surround can now be un-clipped and the entire surround removed

There are 4 tabs along the bottom of the assembly

Once the black surround is off the rest pretty much comes apart with the bottom CCFL tube being able to be removed in a similar manner to the top

The centre of the back light assembly is made up of 4 main parts. A perspex sheet with white plastic coating, 2 opaque matt plastic sheets, and 1 Pearlescent matt plastic sheet

The plastic sheets are polarisers so need to be kept clean and free of dust and scratches

The CCLF tube assemblies are made up of a U shaped reflector with 2ea individual tubes inside. The entire assembly is 457mm long and 7.6mm wide. There are no part numbers on the assembly however there is a S on the end with the wires attached and an 18 on the other end.

The 2 CCFL tubes are held together with a figure 8 rubber band in the middle of the reflector so both tubes must come out at the same time.

The individual tubes are 448mm long (excluding the terminals - standard way to measure is end of glass to end of glass) and are 2.4mm diameter.

The CCFL are soldered to the wires so not a simple plug in replacement

The CCFL are EXTREMELY fragile so ensure you dont break them when installing them.

The CCFL reflectors are a tight fit over the sides of the perspex sheet and the other layers of plastic. Patience and a plastic spudger or pry tool should get you there

The closest I can find to my CCFL measurements are either the 446mm x 2.4mm or the 450mm x 2.4mm so I'd suggest the 446mm is used

See the Removing CCFL from iMac 20in LCD CCFL assembly guide for details

Remove the white tape from either end of the rear of the CCFL assembly.

Carefully remove about 15-20mm of heat shrink from the CCFL cable to allow the end cap to be removed, making sure you DO NOT cut or nick the wire insulation.

The wires have a HIGH VOLTAGE applied during operation and the insulation may break down if damaged causing a short

While holding the assembly, slowly and gently pull the THICK wires up and out of the slots in the white rubber cap.

Pull the wires one at a time ensuring you don't flex the CCFL and break it.

This will reveal the pins and solder joints.

Gently push the THIN wires through the rubber end cap to create a bit of a loop on the rear of the assembly.

Using a plastic pry tool you can pop the rubber end cap out and then lift the thin wires out of the groove in the rear of the CCFL assembly

Note the thin wires are held in the groove by a small amount of adhesive.

Run the pry tool the length of the assembly and free the wires all the way to the other end cap

gently pop the rubber end cap out of the assembly