Mac Laptops Troubleshooting Input/Output Issues
Troubleshooting keyboard functional issues
Troubleshooting keyboard backlight issues
Troubleshooting trackpad issues
Troubleshooting power button or Touch ID issues
Troubleshooting USB-C, Thunderbolt, and HDMI issues
Troubleshooting SD card issues
Troubleshooting keyboard functional issues
Identify issues
When typing, keyboard letters or characters repeat unexpectedly
When typing, keyboard letters or characters aren’t recognized or displayed
When typing, displayed characters don’t match the keys pressed
Key sticky, slow to return upward, or unresponsive
Key stuck in down or up position
Key makes unexpected noise when pressed
Key press feels uneven or stiff
Key doesn’t respond, feels spongy, or doesn’t press all the way down
Keycaps or key switch mechanisms broken or missing
Keyboard locks up
Try quick troubleshooting steps
If a Bluetooth keyboard is present and paired with the computer, unpair it. The keyboard may be overriding input commands from the built-in keyboard.
Inspect the computer for liquid damage. Contact with liquid can short internal circuits and cause the keyboard to stop working.
Make sure that Mouse Keys isn’t turned on. When Mouse Keys is on, the keyboard can’t be used to enter text. Refer to Change Alternate Control Methods preferences for accessibility on Mac for instructions to turn Mouse Keys off.
Refer to steps and support resources in Troubleshooting Quick Checks.
Run manual and diagnostic tests
If the issue wasn’t resolved by following a support article or trying the quick troubleshooting steps, run these diagnostic and manual tests to help isolate the cause of the issue:
If the built-in keyboard isn’t functioning, connect an external keyboard to the computer to continue troubleshooting.
Press the Caps Lock key on the built-in keyboard to ensure that the indicator light illuminates, indicating a partial connection to the logic board. Note that pressing the Caps Lock key on Apple keyboards may not immediately activate the Caps Lock function. The key must be held down slightly longer to activate the Caps Lock function. This is to prevent accidental activation of Caps Lock mode. This is normal behavior and doesn’t indicate a service issue.
Run the Keyboard diagnostic suite.
Note: Diagnostics only verify keyboard electrical operation. Diagnostics don’t verify keyboard mechanical feel and response.
If your MacBook or MacBook Pro has an unresponsive key, or a key that feels different than the other keys when you press it, clean the keyboard.
After cleaning the keyboard, test the keyboard to ensure that all keyboard keys function normally.
If the previous steps didn’t isolate or resolve the issue, refer to the computer’s repair manual to remove and replace the affected keycap to clean and inspect under the keycap. A keycap should always be replaced each time it is removed, even for inspection or cleaning.
Important: Before removing any keycaps, ensure that the correct replacement keycap kit is available. Once a keycap has been removed, it must be replaced by a new keycap. Don’t reuse keycaps.
Clean the inner aluminum part of the keycap well to remove any liquid residue that may be present.
Inspect the scissor mechanism to verify it is functional and has no damaged pins or any other damage. Scissors can also be replaced if damaged.
Inspect the rubber dome for damage. Keycaps and scissor mechanisms can be replaced, but the rubber dome cannot. A damaged rubber dome requires replacement of the entire top case.
Important: In some Mac laptop models, some keyboard and keyboard backlight signals connect to the keyboard through the trackpad flex cable. Trackpad and trackpad flex cable failures may, therefore, cause keyboard issues or unresponsive behavior in both the keyboard and trackpad. If a functioning trackpad and flex cable is available, substitute both and retest for trackpad and keyboard functionality. Replacement of the trackpad or the trackpad flex cable may resolve unresponsive behavior present on both components.
Note: The trackpad flex cable may be part of the trackpad and may not be separately replaceable in some models. Check the repair manual for more information.
Open and inspect the computer
If the issue wasn’t resolved or isolated by following support articles or running diagnostics tests, refer to the computer’s repair manual to open and inspect the computer. A damaged or out-of-place part may be causing one of the issues.
Follow repair manual procedures to remove the bottom case and disconnect the battery from the logic board.
Some laptop models use a lid angle sensor to detect when the display lid is opened and closed. A malfunction of the lid angle sensor module can affect keyboard and trackpad operation.
Some laptop models, such as MacBook Pro (13-inch, M1, 2020), have a keyboard flex cable that is part of the top case assembly. On other laptop models, such as MacBook Air (M1, 2020), keyboard backlight signals connect through a combined IPD flex cable and board. Locate all keyboard and IPD flex cable connectors (depending on the model) and verify all cables are present and connected. If a keyboard or IPD flex cable is missing, it may be under the logic board or another board. Remove boards to locate the flex cable.
Replace any damaged flex cables.
Carefully reinstall and reseat all keyboard or IPD flex cables. Reassemble the computer and run diagnostics again.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Replace the part
If your issue wasn’t resolved or isolated by following the previous steps, replace the top case assembly.
If the trackpad or the trackpad flex cable is found to cause keyboard functional issues, replace the trackpad or the trackpad flex cable.
After the repair is completed, turn on the computer and verify that the keyboard and trackpad are both functioning normally. Run the Keyboard diagnostic suite to verify that all keys are functional after repair, including modifier keys.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Troubleshooting keyboard backlight issues
Identify issues
Keyboard operation is normal except backlight isn’t working as expected
Keyboard backlight isn’t activated in a darkened room
Keyboard backlight is uneven
Part of the keyboard isn’t illuminated
Try quick troubleshooting steps
Ensure that the ambient light sensor isn’t covered. It’s located at the top of the computer display near the camera. The keyboard backlight uses the ambient light sensor to illuminate in low-light conditions.
Inspect the computer for liquid damage. Contact with liquid can short internal circuits and cause the keyboard to stop working.
Refer to steps and support resources in Troubleshooting Quick Checks.
Run manual and diagnostic tests
If your issue wasn’t resolved by following a support article or trying the quick troubleshooting steps, run these diagnostic and manual tests to help isolate the cause of the issue:
If the built-in keyboard isn’t functioning, connect an external keyboard to the computer to continue troubleshooting.
Press the Caps Lock key on the built-in keyboard to ensure that the indicator light illuminates, indicating a partial connection to the logic board.
Note: Pressing the Caps Lock key on Apple keyboards may not immediately activate the Caps Lock function. The key must be held down slightly longer to activate the Caps Lock function. This is to prevent accidental activation of Caps Lock mode. This is normal behavior and doesn’t indicate a service issue.
Run the Keyboard diagnostic suite.
Check ambient light sensor (ALS) functionality by covering the sensor (located on the display assembly near the camera) with your hand to simulate a dark room. Check whether the keyboard backlight brightness increases.
Keep the ALS covered and use controls to increase the keyboard backlight level.
Open and inspect the computer
If the issue wasn’t resolved or isolated by following support articles or running diagnostics tests, refer to the computer’s repair manual to open and inspect the computer. A damaged or out-of-place part may be causing one of the issues.
Follow repair manual procedures to remove the bottom case and disconnect the battery from the logic board.
Some laptop models have a keyboard backlight flex cable that is part of the top case assembly. On other laptop models, keyboard backlight signals connect through a combined IPD flex cable and board. Some models may have more than one keyboard backlight flex cable. Each cable drives part of the keyboard backlight (left or right side). On some models, power to both sides is supplied by a third cable.
Locate all keyboard backlight and IPD flex cable connectors (depending on the model) and verify that all cables are present and connected. If a keyboard or IPD flex cable is missing, it may be under the logic board or another board. Remove boards to locate the flex cable.
Retest in low-light conditions to activate the keyboard backlight. Adjust the keyboard backlight using controls.
Important: In some Mac laptop models, some keyboard and keyboard backlight signals connect to the keyboard through the trackpad flex cable. Trackpad flex cable failures may, therefore, cause keyboard issues or unresponsive behavior in both the keyboard and trackpad. If a functioning trackpad flex cable is available, substitute it and retest for trackpad and keyboard functionality. Replacement of the trackpad flex cable may resolve unresponsive behavior present on both components.
Note: The trackpad flex cable may be part of the trackpad and may not be separately replaceable in some models. Check the repair manual for more information.
Replace any damaged flex cables.
Carefully reinstall and reseat all keyboard backlight flex cables. Reassemble the computer and run diagnostics again.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Replace the part
If the issue wasn’t resolved or isolated by following the previous steps, replace the top case assembly.
After the repair is completed, turn on the computer and verify that the keyboard and keyboard backlight are functioning normally.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Troubleshooting trackpad issues
Identify issues
Cursor doesn’t move with trackpad input
Multi-Touch features don’t function as expected
Trackpad doesn’t respond to clicks
Trackpad has haptic feedback issues
Try quick troubleshooting steps
Turn off the computer. Then clean the trackpad surface using a soft, lint-free cloth.
Visually inspect the trackpad for damage to ensure that factors such as humidity, hand lotion, or jewelry haven’t affected the functionality of the trackpad. Avoid touching the trackpad simultaneously with both hands.
In System Settings > Accessibility, disable all assisted Keyboard and Mouse & Trackpad settings. Retest trackpad functionality.
In System Settings > Trackpad, check and adjust Click pressure and Trackpad speed. Too-high or too-low settings may be perceived as trackpad issues.
Disconnect all Bluetooth devices. In System Settings > Bluetooth, click the “X” button next to every device.
Refer to steps and support resources in Troubleshooting Quick Checks.
Run manual and diagnostic tests
If the issue wasn’t resolved by following a support article or trying the quick troubleshooting steps, run these diagnostic and manual tests to help isolate the cause of the issue:
If the built-in trackpad isn’t functioning, connect an external mouse or trackpad to the computer to continue troubleshooting.
If the trackpad isn’t working, the computer may be showing a low battery alert that you can’t see. Connect the computer to a power adapter to see the alert.
Run the Trackpad diagnostic suite.
Some laptop models use a lid angle sensor to detect when the display lid is opened and closed. A malfunction of the lid angle sensor module can affect keyboard and trackpad operation. .
Important: In some Mac laptop models, some keyboard and keyboard backlight signals connect to the keyboard through the trackpad flex cable. Trackpad flex cable failures may, therefore, cause keyboard issues or unresponsive behavior in both the keyboard and trackpad. If a functioning trackpad flex cable is available, substitute it and retest for trackpad and keyboard functionality. Replacement of the trackpad flex cable may resolve unresponsive behavior present on both components.
Note: The trackpad flex cable may be part of the trackpad and may not be separately replaceable in some models. Check the repair manual for more information.
Open and inspect the computer
If the issue wasn’t resolved or isolated by following support articles or running diagnostics tests, refer to the computer’s repair manual to open and inspect the computer. A damaged or out-of-place part may be causing one of the issues.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Replace the part
If the issue wasn’t resolved or isolated by following the previous steps, replace the trackpad. If the trackpad isn’t available as a separate part, replace the top case assembly, which contains the trackpad in some models.
After the repair is completed, turn on the computer and verify that the trackpad is functioning normally.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Troubleshooting power button or Touch ID issues
Identify issues
Read this article if you notice any of the following issues:
Power button doesn’t click properly or at all
Power button has a stiff or spongy feel when pressed
Touch ID is unable to read fingerprint
Unable to enroll a finger in Touch ID
Unable to unlock computer using Touch ID
Unable to make a purchase using Apple Pay and Touch ID
Touch ID issues after logic board replacement
If Touch ID isn’t working on your Mac
If the issue wasn’t resolved by following a support article, continue to the next section.
Try quick troubleshooting steps
Ensure that your fingers and the Touch ID sensor are clean and dry. Use a soft, lint-free cloth to wipe off any dirt or debris on the Touch ID sensor.
Refer to steps and support resources in Troubleshooting Quick Checks.
Run manual and diagnostic tests
If the issue wasn’t resolved by following a support article or trying the quick troubleshooting steps, run these diagnostic and manual tests to help isolate the cause of the issue:
Run the Touch ID diagnostic suite.
Open and inspect the computer
If the issue wasn’t resolved or isolated by following support articles or running diagnostics tests, refer to the computer’s repair manual to open and inspect the computer. A damaged or out-of-place part may be causing one of the issues.
For issues with power button feel, remove the bottom case and disconnect the battery from the logic board. Inspect the gap between the top case and the Touch ID board for debris. If any debris is found that may interfere with power button operation, use compressed air to clean out the debris.
Fixing a power button that doesn’t click properly or feel right requires the use of Touch ID shims or turning a center set screw (depending on the model). Refer to the computer’s repair manual to determine which button adjustment type is relevant to your model.
For models with a set screw, refer to the computer’s repair manual to change the click tactility of the Touch ID and power button using the center set screw to correct the issue.
For models with shims, a Touch ID button that feels too loose or too stiff can be caused by installing an incorrect shim that is too large or small. If the Touch ID button isn’t aligned, refer to the computer’s repair manual to realign the Touch ID board in the top case. If the button feels too loose or has a spongy feel, use a larger shim. If the button feels too stiff or doesn’t move, use a smaller shim. Reinstall the same Touch ID board using the new shim.
For issues with Touch ID or power button function, follow repair manual procedures to gain access to the Touch ID board and flex cable. Disconnect the Touch ID board flex cable. Visually inspect all related flex cables and connectors for damage.
Replace any damaged flex cables.
Carefully reinstall and reseat the Touch ID flex cable. Reassemble the computer and run diagnostics again.
For issues with Touch ID after logic board replacement:
On models where Touch ID connects directly to the logic board, the likely cause is the Touch ID board. Replace the Touch ID board. If the issue persists, replace the logic board and Touch ID board.
On other models, Touch ID signals are routed through the audio board flex assembly or another board, such as an interposer board, depending on the model. Audio board or top case with keyboard replacement may resolve Touch ID issues, such as after logic board replacement.
Note: Don’t reinstall the original audio board or top case with keyboard if replacing it doesn’t resolve the Touch ID issue.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Replace the part
If the issue wasn’t resolved or isolated by following the previous steps, replace the Touch ID board, which is also the power button.
After the repair is completed, turn on the computer and verify that the Touch ID or power button issue is no longer present.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Troubleshooting USB-C, Thunderbolt, and HDMI issues
Identify issues
Read these articles if you notice any of the following issues:
USB-C device isn’t recognized or isn’t powered when connected to the computer’s USB-C ports
Thunderbolt device or display isn’t recognized when connected to the computer’s USB-C ports
HDMI display isn’t recognized or doesn’t display an image when connected to the computer’s HDMI port (for models with HDMI)
Identify the ports on your Mac
About the Thunderbolt ports on Mac
Adapters for the Thunderbolt 4, Thunderbolt 3, or USB-C port on your Mac
Change the refresh rate on your MacBook Pro or Apple Pro Display XDR
How many displays can be connected to MacBook Pro
If your external display is dark or low resolution
If the issue wasn’t resolved by following a support article, continue to the next section.
Try quick troubleshooting steps
Ensure that you’re not exceeding the specified maximum number of supported external USB-C devices, Thunderbolt devices, or displays for this model. Refer to Connect a display to your Mac and How many displays can be connected to MacBook Pro for more information about connecting external displays.
Inspect all USB-C and HDMI ports and top case openings on the computer for any signs of deformation, damage, or debris that may be blocking the connection.
If you find any debris in these ports, gently clean each connector using a small, non-metallic, soft-bristled brush. Ensure that the brush is clean and dry. Gently brush out lint or debris. Use just enough bristles to fit inside the connector. Twist the bristles to loosen and lift out debris. Brush debris away from the connector to avoid brushing debris into the connector. Use a microfiber cloth to wipe away the loosened debris.
Caution: Disconnect all cables and turn off the computer. Don’t use aerosol sprays, solvents, abrasives, or cleaners containing hydrogen peroxide that might damage the finish. Don’t use any metal objects to clear debris or obstructions, as this can short the connector and cause damage. Avoid getting moisture in any openings, and don’t spray liquid directly on the computer. Don’t use compressed air.
Refer to steps and support resources in Troubleshooting Quick Checks.
Run manual and diagnostic tests
If the issue wasn’t resolved by following a support article or trying the quick troubleshooting steps, run these diagnostic and manual tests to help isolate the cause of the issue:
Run the Mac Resource Inspector (MRI) diagnostic suite.
Note: For models with HDMI, examine diagnostic results to verify that HDMI hardware is present.
Connect a compatible mouse or keyboard to each USB-C port on the computer to verify basic USB-C port functionality.
Ensure that the Mac recognizes the connection with both orientations of each USB-C connector by flipping the USB-C connector over and reconnecting it.
Connect an external Thunderbolt display to the computer to verify USB-C port Thunderbolt functionality. Verify audio output if the external display has internal speakers. Verify that the external display shows a correct image and that the external display’s speakers produce clear sound.
For models with HDMI, connect an external HDMI display to the computer to verify HDMI port functionality. Verify audio output if the external display has internal speakers. Verify that the external display shows a correct image and that the external display’s speakers produce clear sound.
Open and inspect the computer
If the issue wasn’t resolved or isolated by following support articles or running diagnostics tests, refer to the computer’s repair manual to open and inspect the computer. A damaged or out-of-place part may be causing one of the issues.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Replace the part
If the issue wasn’t resolved or isolated by following the previous steps, replace the following parts one at a time in the order shown. After you replace the first part, repeat the troubleshooting steps to determine whether replacing a part resolves the issue. If it still isn’t resolved, replace the next part.
Replace the input/output board or USB-C board (depending on the model).
Replace the logic board.
After the repair is completed, turn on the computer and verify that known-good USB and Thunderbolt devices are functional and recognized when connected to all USB-C ports on the computer, in both orientations.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Troubleshooting SD card issues
Identify issues
Read this article if you notice any of the following issues:
Can’t insert SD card into slot
Can insert SD card into slot partially, but not completely
SD card slot doesn’t align with enclosure
SD card doesn’t function properly when inserted
Use the SD and SDXC card slot on your Mac
If the issue wasn’t resolved by following a support article, continue to the next section.
Try quick troubleshooting steps
Verify that you’re using the correct type of SD card. Refer to Use the SD and SDXC card slot on your Mac for more information about SD card compatibility and use.
Note: Only some laptop models have SD card slots.
Inspect the SD card slot and top case opening on the computer for any signs of deformation, damage, or debris that may be blocking the connection.
If you find any debris in this slot, gently clean it using a small, non-metallic, soft-bristled brush. Ensure that the brush is clean and dry. Gently brush out lint or debris. Use just enough bristles to fit inside the opening. Twist the bristles to loosen and lift out debris. Brush debris away from the opening to avoid brushing debris into the opening. Use a microfiber cloth to wipe away the loosened debris.
- Caution: Disconnect all cables and turn off the computer. Don’t use aerosol sprays, solvents, abrasives, or cleaners containing hydrogen peroxide that might damage the finish. Don’t use any metal objects to clear debris or obstructions, as this can short the connector and cause damage. Avoid getting moisture in any openings, and don’t spray liquid directly on the computer. Don’t use compressed air.
Refer to steps and support resources in Troubleshooting Quick Checks.
Run manual and diagnostic tests
If the issue wasn’t resolved by following a support article or trying the quick troubleshooting steps, run these diagnostic and manual tests to help isolate the cause of the issue:
Insert a formatted SD card into the computer to verify basic SD card slot functionality. Ensure that the card seats correctly. Remove the card and verify that the card can be removed without difficulty.
Verify that the SD card reader hardware is intact and not damaged. The SD card reader is typically part of the logic board.
Open and inspect the computer
If the issue wasn’t resolved or isolated by following support articles or running diagnostics tests, refer to the computer’s repair manual to open and inspect the computer. A damaged or out-of-place part may be causing one of the issues.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.
Replace the part
If the issue wasn’t resolved or isolated by following the previous steps, replace the logic board, which contains the SD card reader.
After the repair is completed, turn on the computer and verify that known-good SD cards are functional and recognized when inserted into the SD card slot on the computer.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the device’s issue. You can find other service options at support.apple.com/repair.