Mac Modular Desktops Troubleshooting Power and Startup Issues
Troubleshooting intermittent shutdown or system instability
Troubleshooting startup issues
Troubleshooting intermittent shutdown or system instability
Identify issues
Read these articles if you notice any of the following issues:
The computer shuts down during startup
The computer shuts down unexpectedly during use
The computer restarts and displays an alert message
The computer doesn’t respond after startup
The computer doesn’t respond after waking from sleep
The computer has slow performance
If your Mac doesn’t start up all the way
If your Mac restarted because of a problem
If your issue wasn’t resolved by following a support article, continue to the next section.
Try quick troubleshooting steps
Collect the following details and correlate related symptoms with possible causes:
When shutdown occurs (for example, after running for a while)
Frequency of shutdowns
Which applications are running at the time
Shutdown repeatability
Inspect the computer for indications of liquid spills. A liquid spill can short internal circuits and stop fan operation.
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 checking for potential causes, run these diagnostic and manual tests to help isolate the cause of the issue:
Attempt to start up in Safe Mode to verify that the computer can start up completely without any issues.
Run the Mac Resource Inspector (MRI) diagnostic suite.
Note: This test will gather diagnostic information and verify that thermal sensor readings are within limits. Check MRI results for any power, fan, or thermal warnings or failures.
Open and inspect the computer
If your 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 open the computer.
Inspect internal components and the enclosure for indications of physical or liquid damage, contamination, or burned or darkened areas.
Inspect the area around the heat sink and each fan for accumulated dust or debris. Use an ESD-safe vacuum or compressed air to carefully remove dust and debris from the heat sink and fans. Ensure that each fan spins freely and is not obstructed.
For computers with internal expansion, such as Mac Pro, simplify the troubleshooting process by removing unnecessary peripherals, internal expansion cards, and other optional items from the computer being tested. Bringing the computer’s configuration back to a minimum state can help you isolate and resolve issues involving: no power, power but no video, or other startup-related symptoms. This method gradually builds up the system from a minimum configuration and verifies expected behaviors at each step.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the computer’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 troubleshooting steps above, replace the logic board.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the computer’s issue. You can find other service options at support.apple.com/repair.
Troubleshooting startup issues
Identify issues
Read these articles if you notice any of the following issues:
The computer doesn’t start up completely when it’s turned on
The computer displays an icon of an exclamation point (!) inside a circle
The computer initially appears to be turned off but shows signs of power, such as a spinning fan or status indicator light
If your Mac doesn’t start up all the way
If your Mac restarted because of a problem
If your Mac starts up to an exclamation point in a circle
If your Mac starts up to Options with a gear icon
If you can’t start up from macOS Recovery
Use macOS Recovery on a Mac with Apple silicon
If your issue wasn’t resolved by following a support article, continue to the next section.
Try quick troubleshooting steps
Inspect the computer for indications of liquid spills. A liquid spill can short internal circuits and stop fan operation.
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 checking for potential causes, run these diagnostic and manual tests to help isolate the cause of the issue:
Determine if the computer has power by confirming any of the following:
Status indicator light illuminates
Fan spins
A connected external display functions
If the computer shows no indications of power, refer to troubleshooting no power.
Attempt to start up in Safe Mode to verify that the computer can start up completely without any issues.
Run the Mac Resource Inspector (MRI) diagnostic suite.
Note: This test will gather diagnostic information and verify that thermal sensor readings are within limits. Check MRI results for any power, fan, or thermal warnings or failures.
Connect a compatible external display to the computer. Check for an image on the connected external display.
Attempt to start up the computer to macOS Recovery. Verify that the computer starts up to macOS Recovery.
While started up to macOS Recovery, use Disk Utility to verify the computer’s internal startup volume. If you notice errors, use Disk Utility to repair the computer’s internal startup volume.
Restart the computer and verify that it completes the startup process. If the computer still doesn’t start up completely, select the Install macOS option in macOS Recovery to update or reinstall macOS.
If the computer can’t start up to macOS and can’t start up to macOS Recovery, an icon with an exclamation point inside a circle appears. If you see this icon when attempting to start up the computer, follow the recommended steps in If your Mac starts up to an exclamation point in a circle.
Open and inspect the computer
If your 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 open the computer.
Inspect internal components and the enclosure for indications of physical or liquid damage, contamination, or burned or darkened areas.
Inspect the area around the heat sink and each fan for accumulated dust or debris. Use an ESD-safe vacuum or compressed air to carefully remove dust and debris from the heat sink and fans. Ensure that each fan spins freely and is not obstructed.
For computers with internal expansion, such as Mac Pro, simplify the troubleshooting process by removing unnecessary peripherals, internal expansion cards, and other optional items from the computer being tested. Bringing the computer’s configuration back to a minimum state can help you isolate and resolve issues involving: no power, power but no video, or other startup-related symptoms. This method gradually builds up the system from a minimum configuration and verifies expected behaviors at each step.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the computer’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 logic board.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the computer's issue. You can find other service options at support.apple.com/repair.
Troubleshooting no power
Identify issues
Read these articles if you notice any of the following issues:
The computer doesn’t turn on when you press the power button
No image appears on a connected external display
Status indicator light does not illuminate
Identify your Mac Studio model
Mac computer status indicator light behavior
Mac Pro (2023) status indicator light behavior
If your Mac doesn’t start up all the way
If your Mac starts up to an exclamation point in a circle
If your Mac starts up to Options with a gear icon
If you can’t start up from macOS Recovery
Use macOS Recovery on a Mac with Apple silicon
If your issue wasn’t resolved by following a support article, continue to the next section.
Try quick troubleshooting steps
Inspect the computer for indications of liquid spills. A liquid spill can short internal circuits and stop fan operation.
Verify that the computer is turned off. If you aren’t sure if the computer is on or off, press and hold the power button to turn off the computer. Wait a few seconds, then press the power button again to turn the computer back on.
Ensure that the power cord is functional and securely attached to the computer.
Refer to steps and support resources in Troubleshooting Quick Checks.
Run manual tests
If your issue wasn’t resolved by following a support article or checking for potential causes, run these manual tests to help isolate the cause of the issue:
Determine if the computer has power by confirming any of the following:
Status indicator light illuminates
Fan spins
A connected external display functions
If the computer shows any indications of power, refer to troubleshooting startup issues.
Open and inspect the computer
If your 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 open the computer.
Inspect internal components and the enclosure for indications of physical or liquid damage, contamination, or burned or darkened areas.
Inspect the area around the heat sink and each fan for accumulated dust or debris. Use an ESD-safe vacuum or compressed air to carefully remove dust and debris from the heat sink and fans. Ensure that each fan spins freely and is not obstructed.
For computers with internal expansion, such as Mac Pro, simplify the troubleshooting process by removing unnecessary peripherals, internal expansion cards, and other optional items from the computer being tested. Bringing the computer’s configuration back to a minimum state can help you isolate and resolve issues involving: no power, power but no video, or other startup-related symptoms. This method gradually builds up the system from a minimum configuration and verifies expected behaviors at each step.
For Mac mini models with an antenna connector board, verify that this board is connected firmly to the logic board with its flex cable. Verify that the flex cable is not damaged. Verify that the power button is not damaged and is connected firmly to the antenna connector board. Verify that the power button cable is not damaged. Power button signals travel through these cables and this board to the logic board.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the computer’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 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 power supply.
Replace the power button in Mac mini models with an antenna connector board.
Replace the antenna connector board or its flex cable in Mac mini models with that component.
Replace the logic board.
Note: This section requires ordering parts and tools. Replacing a part may not resolve the computer’s issue. You can find other service options at support.apple.com/repair.