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General Troubleshooting

Troubleshooting for Screen Replacement

Hey anyone doing a repair can encounter a hiccup. Don't worry, relax, count to 10 and then review these troubleshooting steps. This will fix a lot of issues.

General Troubleshooting Steps

1. First do a soft reset of your device and check if this helps.

2. Make sure your device is charged.

3. Confirm you have the right part for your device.

Many parts are very similar, but parts are specific to a device and models. Use our handy guides Find my model# > to check your model number and then review against the new part. Also you can compare the new part to your original part to see if they are the same.

4. Check all cables and connections to make sure they are securely connected and no pins are bent. These are fragile so be careful and do not bend or pull.

5. Clean the connectors like the digitizer flex cable and carefully attempt to reattach the cables.

Dirt and dust can disrupt the contacts. For cleaning, we recommend using 95% or higher alchol on a q-tip. You can also use pressurized air to blow out direct. Do a soft reset after reconnecting any cables.

6. Review troubleshooting below for specific issues and tips.

7. Last, try reinstalling your old part and see if that fixes the issue.

If you need more help, then check what other people are saying about a repair. Send us an email or chat in so the RepairPartsPlus team can help! You can reach us at We also love to get photos of the issue.

More Troubleshooting for specific issues

Issue # 1: iPhone does not turn on and now has a black or white screen

Explanation: This is normally a software calibration issue. Blank and white screens are usually a sign of the internal software not wanting to accept the new parts.

Video Guide:

Troubleshoot Steps A:

  • Do a soft reset by pressing both the home and power button for 15 seconds. A soft reset will clear your device of any temporary data that is blocking your new part from working.

  • Troubleshoot Steps B:

    1. If step A does not work, try disconnecting the battery connection and holding the power button down for twenty second. Then reattach the battery and hold down the power button.

    2. If steps above don't work, try to reseat the battery again with steps below.

    A. Re-seat the battery connector and the connectors for the LCD or Digitizer.

    B. When reconnecting the cables back onto the board, ensure that the pins align properly and that you get a tactile click when reconnecting.

    C. Reconnect all connectors for the screen.

    D. Lastly, connect the battery connector. Close everything up and power on the device.


    Things to Note:

    · Check to see if your screens’ back light is on.

    · If there is no back light in addition to no display, your new LCD is not plugged in correctly.

    · Reattempt the repair and make certain your new part is fully installed.


    Troubleshoot Steps C:

    Follow link to How to do force restart if your screen is black or frozen

    Issue #2: If your digitizer is unresponsive and does not detect touch on the screen

    1. Reattempt the repair

    2. Make sure that the flex cable is not the damaged, torn or crimped (excessively folded).

    Note: Crimping causes micro fracturs in the think metal inside a flex cable. Once this metal is cracked, power and other impulses cannot flow through the device.

    Issue #3: If only a select grid of icons will not work such as the top third, or left side

    Explanation: You may have a cable that is miss aligned.

    Troubleshoot Steps:

    1. Open your device and make certain that all the connectors on the flex cable match up.

    2. If this plug is off center, you will see a “blocking” problem.

    Note: Blocking can happen if either your digitizer cable or motherboard have missing or bent pins.

    3. The missing or bent pins will need to be put back into place before your device can continue working again.

    Issue #4: Stress marks on your device shows yellow discolorations or ink like blotches on your display (commonly near the edges)

    Explanation: Stress marks is a potential sign that too much pressure has been applied to the LCD during the repair process.

    Troubleshoot Steps A:

    1. Open your device and make certain that there is no residual glass form your original broken screen.

    2. After clearing your screen, disable your phone’s “sleep mode” and leave your device on a charge for 24 hours.

    Note: The heat from a constant charge can cause the crystals inside your device to move back into place.

    Troubleshoot Steps B:

    1. If step A does not resolve the problem, do the following steps

    Note: Stress marks can be the result of the pressure that is applied from placing your finger directly on the back of the LCD screen, during the repair process.

    2. Remove the LCD assembly

    3. Thoroughly clean the metal frame from all glass, glue, and tape.

    Note: Possible residual 3M tape or glue will need to be removed before attempting reinstallation process. Any residue is interfering with proper electrical connections

    4. Re-process installation

    Issue #5: Your device is showing blue or black bars.

    Explanation: This is normally a sign of your LCD cable not being plugged in correctly.

    Troubleshoot Steps:

    1. Re-attempt the repair process from the beginning.

    2. At the point where you plug in your new screen to your main board, check both your connector plugs, and verify that none of the pins are bent or missing.

    3. If the pins are damaged, plugging in your new screen again will not solve the problem.

    4. You will need to bend the pins back into place before your device will start working again.

    5. Once the pins are straight, and the screen is plugged in again, try powering on your device without closing it up.

    Note: This will allow you to troubleshoot your repair without the need to remove every screw all over again.

    Issue #6: If your device is showing no image, but there is a glow from the back light

    Explanation: This is normally a sign of your LCD cable not being plugged in correctly.

    Troubleshoot Steps:

    1. Unplug your screen & battery

    2. Re- plug your screen.

    3. Plug your device into iTunes (see if you have an image).

    4. If an image appears, unplug your device from iTunes.

    5. Plug your battery back in.

    6. Turn your device on using the power button.

    Issue #7: If your device is showing no image, but there is a glow from the back light and have tried all steps for issue 5 & 6. You may have a battery that is dead or dying

    Explanation: Current battery is no longer sending a strong enough charge to your phone to allow the screen to make an image appear. You will need to replace your battery.

    Things to Note:

    · Should an image appear on your phone, you are ready to go.


    Issue #8: (iPhone 6 specific) The digitizer is working intermittently. The display is flickering or is experiencing multi-touch issues.

    Explanation: In the past, customers has reported that iPhone 6 Plus, and some iPhone 6, has a problem called Touch Disease (see apple class action lawsuit). The “touch disease” is a gray flickering bar with touch screen responsiveness problems. It often happens after phone has been dropped.

    Things to Note:

    Apple Website:

    · Please refer to the warranty on your device and consult with an Apple Genius at the apple store

    Issue #9: When the screen is mounted onto the iPhone, the screen displays two black vertical lines and disappears once taken off.

    Explanation: Lines are normally caused when the LCD cable is not correctly aligned in or some dust is trapped in the connectors themselves.

    Troubleshoot Steps:

    1. Remove the LCD Screen and clean the connectors

    Things to Note:

    · If the troubleshooting does not work or if your screen still displays vertical lines, you may have a defective or broken part.

    Issue #10: Sometimes the screen is unresponsive or lags

    Troubleshoot Steps A:

    1. Since the issue occurs intermittently, check if the phone software is causing this issue.

    2. Back up your phone data then restore your device.

    3. Make sure to setup your phone as a new device.

    4. Once this is done check the swipe functionality and see if the issue still occurs.

    5. If it doesn’t then it was probably caused by a software glitch. You can now restore your data to your phone.

    Troubleshoot Steps B:

    1. If the same issue occurs after restoring your phone, this may be a hardware related issue.

    Note: This may be caused by a loose connection perhaps.

    2. You need to open your phone again and retrace the steps you took during the repair process.

    Issue #11: What to do if the battery replacement is not holding a charge

    Troubleshoot Steps:

    1. Check your battery status on your phone

    On you phone Settings > select battery

    2. Close any apps that are running in the background

    that are consuming too much power

    3. Check background app activity> in setting go to General and Background App Refresh.

    4. Here you can check to see which apps are running in the background and check to see percentage of usage by app.

    5. To save battery life, you can either turn off background app and refresh all together

    6. After having done step 1 and 2, you still experiencing fast battery drain you may need to calibrate the battery.

    7. Calibrating a battery is easy. Let your Phone’s battery drop to 0% and until it shuts off automatically. Then let it charge uninterrupted back to 100%

    Issue: Screen is black, but the iPhone is still working

    The iPhone screen works, but the screen is black. The backlight is not working. When attaching the screen, you may have noticed a puff of smoke and smelt a burn odor.

    To confirm that the backlight is no longer working, disconnect the battery, reconnect it, then plug in a USB lightning cable. Immediately shine a bright light on the center the screen and you should be able to see a faint apple logo. That will confirm that there is a problem. This can happen if the iPhone is not turned off or the battery is not disconnect before starting repair. With the iPhone 6s and the iPhone 6s Plus the Backlight Circuit still receives power when the phone is powered off so you have to disconnect the battery as well.

    To resolve, you will need to replace the Backlight Circuit or the complete LCD.