Apple iPod Touch 4th Generation – Disassembling procedure

iPod Touch 4th Generation – Disassembling procedure – How to remove and replace the display
 Apple iPod Touch: DISASSEMBLING PROCEDURE 

The iPod Touch 4th Generation front panel is attached to the rear case by adhesive. The use of a heat gun to soften the adhesive is highly recommended. With the heat gun set on "low", begin heating the lower portion of the Touch near the home button. t is suggested to heat the desired portion in a circular motion pattern to evenly dissipate the amount of heat throughout the device.

Beware, as the Touch will be very hot. It may be helpful to hold it with a towel while prying. Insert the edge of an iPod opening tool between the front glass panel and the plastic bezel near the home button. Do not try to pry between the plastic bezel and the steel rear case. Pry the bottom edge of the front panel upward, being careful not to bend the glass excessively. If it is too difficult to pry up the front panel assembly, reheat it and try again.

When there is enough room to grab the bottom edge of the front panel, lift it away from the body of the Touch to peel up the adhesive along its left and right edges. If the adhesive is too difficult to separate, use a heat gun to soften it before proceeding.

Due to the construction of the 4th generation Touch, the digitizer cable cannot be disconnected until the logic board is removed. Use extreme caution when handling the front panel assembly, as it is attached to the rest of the Touch by the very delicate digitizer cable. Also, the display data cable is very short and is connected to the logic board near the top of the front panel assembly. If it does not become disconnected while freeing the top edge of the front panel assembly, be sure to disconnect it with an iPod opening tool before rotating the front panel assembly out of the Touch. Carefully pull the top of the front panel assembly away from the adhesive holding it to the Touch, minding the short digitizer cable connecting the two components.

Remove the following eight Phillips #00 screws:

One 3.5 mm Phillips screw
Two 3.0 mm Phillips screws
One 2.3 mm Phillips screw
One 2.4 mm Phillips screw
Three 2.0 mm Phillips screws

Use the edge of an iPod opening tool to pry the thin steel cover up from the rear-facing camera. Note the small spring located near the bezel next to the camera (highlighted in yellow). Remove the steel cover from the iPod.

Insert the edge of an iPod opening tool under the steel mid plate near the bottom left corner of the Touch. Pry upward to separate the plate from the adhesive securing it to the plastic inner case. If the plate is still attached to the logic board re-warm the area to loosen the adhesive, then separate the plate from the logic board using the opening tool Use extreme care, the speaker is under the area shown in photo. It is connected with very thin and short wires. There is a very thin ribbon cable here that connects the volume and power buttons to the logic board. Try to work around this area like shown so not to rip the cable. Be sure to hold down this cable when lifting the plate. It could stick to the plate due to residual glue. It is extremely fragile.

This cable will tear very easily if you are not careful.
There is also adhesive under the area shown in red.

Slightly tilt the steel mid plane to dislodge it from the rear case. Be careful not to tear the piece of copper tape connecting the rear-facing camera to the steel mid plane. Lift the steel mid plane up off the rear case and peel off the piece of copper tape stuck to the rear-facing camera.

Remove the three screws near the top edge of the logic board:

One 2.0 mm Phillips screw

Two 2.3 mm Phillips screws

Use the edge of an iPod opening tool to gently pry, but not remove, the rear-facing camera away from the rear case. Do not attempt to remove the rear facing camera yet.

Use an iPod opening tool to slightly lift the edge of the logic board next to the battery enough to grab it with your other hand. Do not excessively bend the logic board, as it is very thin and fragile. Be very careful not to lift too much as the volume control ribbon cable is still connected and will tear very easily. While gently lifting the logic board with one hand, use an iPod opening tool to lift the logic board near the copper tape at the logic board's top edge. The logic board will be lifted adequately when the last display assembly connector has cleared the top edge of the rear case.

Use the edge of an iPod opening tool to begin peeling the loop of copper tape wrapped around the connector near the center of the top edge of the logic board. Continue peeling the tape until it is free from the logic board. Using a pair of tweezers to peel the tape greatly simplifies the task if you've got them.

Use the edge of an iPod opening tool to pry the connector out of its socket on the logic board. Remove the front panel assembly from the Touch. If you are installing a new display assembly, you will want to replace the old adhesive with new adhesive. Remove as much of the old adhesive as you can and then apply new adhesive strips to the appropriate places.

You will also need to transfer the metal plate that sits over the front camera and sensor windows. You can do this using a heat gun or hair dryer.
After you have reassembled your device, it is common to get a white screen when powering it up for the first time. All you have to do is a soft reset and that should fix it. This is accomplished by holding down the power button and the home button until it restarts, or running the battery all the way down until it turns off. Double check that the ribbon cable is not pinched between the LCD and the metal plate. Fold it back on itself so that it doesn't get pinched. If the ribbon cable is pinched, you may get a white screen that cannot be fixed because the traces on the ribbon cable have been damaged.