iPhone 4 Power & Lock Button Replacement - iPhone 4

Step 1 | Rear Panel

To start the repair, ensure the iPhone's battery has a charge level of less than 25%; a fully charged lithium-ion battery presents a fire or explosion hazard if damaged.
Prior to starting the iPhone's disassembly process, ensure the device is completely de-energized.
The iPhone 4's back cover is secured with either two #000 Phillips head screws or Apple's 5-Point 'Pentalobe' screws, as shown in the second image. Verify the screw type present and confirm you possess the corresponding screwdriver for proper removal.
Using either a Pentalobe or Phillips #000 screwdriver, detach the two screws measuring 3.6 mm located adjacent to the dock connector.
To prevent damage, ensure the driver is fully engaged with each Pentalobe screw before turning, as these screws are prone to stripping.

Step 2

Apply pressure to the back cover, directing it upwards, and it should shift approximately 2 millimeters.

Step 3

To detach the rear panel, either gently raise it by applying upward pressure with your fingers or secure a Small Suction Cup to the panel and lift.
Exercise caution to prevent harm to the plastic clips affixed to the rear panel.
Before attaching a replacement rear panel, peel away the adhesive backing from the protective layer covering the camera lens’s interior surface, and also remove the sticker adhered to the large black area positioned close to the lens.

Step 4 | Battery

Using a Phillips screwdriver, detach the battery connector from the logic board by unscrewing the single 2.5 mm screw that holds it in place.
Certain models incorporate a second screw; this secures the contact pad situated directly above the screw highlighted in red within the accompanying image.

Step 5

Carefully lift the battery connector away from its corresponding socket on the logic board, utilizing a plastic opening tool to avoid damage.
To avoid connector damage, carefully separate the bracket from the top and bottom surfaces, as the side edges offer minimal clearance.
Exercise extreme caution when releasing the battery connector, ensuring you apply force only to the connector itself, as applying pressure to the logic board socket risks irreparable damage.
Carefully detach the metal clip, which secures the antenna connector.

Step 6

Carefully extract the battery from the iPhone by utilizing the provided transparent plastic tab to raise it.
Should the retaining tab fracture prior to battery separation, introduce several drops of isopropyl alcohol with a concentration exceeding 90% beneath the battery's edge. Allow approximately one minute for the alcohol to dissolve the adhesive bond. Then, gently use a spudger to disengage the adhesive and free the battery.
To avoid damage, do not force the battery removal; instead, if adhesion persists, add additional drops of alcohol to soften the adhesive. Ensure the pry tool does not puncture or warp the battery during the process.
To prevent damage, ensure any residual alcohol solution is completely removed by wiping with a clean cloth or by permitting it to evaporate fully prior to battery installation.
Carefully discard the protective plastic packaging that accompanied the new battery by gently separating it from the ribbon cable.
Ensure the red contact clip is correctly situated adjacent to the battery connector prior to reattaching the battery connector.
To prevent wireless interference, thoroughly remove any residue from metal surfaces that will touch each other during reassembly, using a cleaning agent like Windex.
Following reassembly, execute a complete system reset to proactively avoid potential problems and streamline any subsequent diagnostic procedures.

Step 7 | Logic Board

To remove the SIM card and its tray, carefully insert a SIM card eject tool or a straightened paperclip into the designated release aperture.
Applying considerable pressure might be necessary.
Carefully extract the SIM card from its tray, then detach the tray completely.

Step 8

Using the appropriate screwdriver, detach the two screws.
Use a Phillips screwdriver, size 1.2 mm.
Use a Phillips screwdriver, size 1.6 mm.
Carefully detach the slender steel cable cover, which protects the dock connector, from the iPhone.
To prevent wireless interference, thoroughly remove any oils or residue from all surfaces where the dock connector cable cover makes contact with other metal parts, using a cleaning agent like Windex.

Step 9

Carefully lift the dock cable connector's two ends away from the logic board using an iPod opening tool, applying gentle force.

Step 10

Using caution, detach the dock ribbon cable from both the logic board and the lower speaker enclosure.
Carefully detach the dock ribbon cable from the logic board, avoiding any strong pulling that could damage it.

Step 11

Carefully lift the lower antenna connector from its socket on the logic board using a plastic opening tool.

Step 12

Using a Phillips screwdriver, detach the logic board from the inner case by unscrewing the 1.9 mm screw located at its base.

Step 13

To detach the Wi-Fi antenna from the logic board, unscrew these five Phillips screws, noting their sizes: a 2.3 mm, two 1.6 mm, one 1.4 mm, and one 4.8 mm. During reassembly, initially secure the 4.8 mm screw, followed by the 2.3 mm screw, to prevent errors that could damage the LCD and digitizer. Ensure the 4.8 mm screw is properly positioned during reassembly, as it serves as the Wi-Fi antenna's ground connection and can cause poor Wi-Fi signal if incorrectly placed.

Step 14

Carefully separate the Wi-Fi antenna's upper edge from the logic board by gently prying with an iPod opening tool. Then, detach the Wi-Fi retaining clips from the internal frame using a spudger. When removing the antenna, be certain to retain the two metal clips located on the cover’s top edge—they secure with a 4.8mm screw, and their loss is a common cause of poor Wi-Fi function following repair. Prior to reassembly, thoroughly clean all metal contact areas on the connector cover with a de-greaser like Windex to eliminate oils that could interfere with wireless signals; however, avoid applying Windex directly to the connectors themselves.

Step 15

Employing an iPod opening tool, gently disengage the rear camera connector from its socket on the logic board, then detach the rear camera.

Step 16

Carefully peel away the small, round, white label—which contains the warranty validation and water damage indicator—that obscures the screw positioned close to the battery release tab.
Carefully peel back the sticker to access and unscrew the 2.4 mm Phillips screw located beneath it.

Step 17

Carefully lift each of the specified connectors from their corresponding sockets on the logic board, employing the edge of a plastic opening tool to avoid damage.

Carefully release the digitizer cable by gently separating it from its connection point located underneath the device.
Carefully release the LCD cable by applying upward pressure from beneath.
Carefully separate the headphone jack and volume button cable assembly from the device's upper surface using prying tool.
Carefully detach the microphone/sleep button cable by gently separating it from the upper assembly.
Carefully detach the front camera cable by gently levering it upwards from its connector location at the top of the device.

Step 18

Using the appropriate tool, detach the 4.8 mm standoff screw located close to the headphone jack.
Employ a standoff screwdriver or bit to extract standoff screws.
If a dedicated tool isn't available, a small flathead screwdriver can be carefully employed; however, exercise heightened vigilance to prevent slippage and potential harm to nearby parts.
To ensure proper assembly, position the Wi-Fi shield—previously removed in step 13—so it's level with the frame using this standoff, which dictates its height. Failure to adequately tighten this standoff will prevent the back cover from sliding into place during step 2 because the shield will protrude; the shield's surface must be even with the headphone jack.
To guarantee proper alignment during reassembly, position the motherboard's edge so it rests beneath the designated standoff, as indicated by the circle; failure to do so will prevent screw installation.
Confirm the tiny rubber spacer, previously affixed to the motherboard's upper surface, is correctly positioned during reassembly.
Absence of this component risks damage to the surrounding ribbon cables on the motherboard.

Step 19

Detach the iPhone's logic board with caution, ensuring no cables are snagged during removal.
Exercise caution to avoid harming the delicate, gold-colored projection—identified by a red mark and located close to the upper portion—due to its vulnerability.
Ensure the lower antenna cable is routed clear of the logic board during reassembly to prevent pinching or damage.

Step 20 | Front Facing Camera

Carefully pry the steel front camera retainer away from the front camera assembly using the edge of a plastic opening tool.
Carefully detach the front camera securing clip.
Align the clip so its tabs face outward, fitting them into the corresponding metal slots.

Step 21

Gently detach the front camera assembly from the iPhone, ensuring no damage occurs.
Reattaching the front camera retainer is easier with tweezers.

Step 22 | Power & Lock Button

Using a Phillips screwdriver, detach the power button bracket from the outer case by unscrewing the two fasteners held in place with 1.5 mm screws.

Step 23

Gently extract the power button bracket from the outer case, exercising caution to avoid damage to the thin, delicate ribbon cable it connects.
Due to the fragile nature of the cast aluminum power button bracket, which is prone to cracking, exercise extreme care when handling it.

Step 24

Carefully extract the power and lock button from the iPhone using tweezers.
Ensure the power button is positioned correctly during reassembly; its metal loop must point downward, and the outer edges should be uppermost.