No Power
Unlikely causes:
Camera, camera/microphone/ALS cable, CPU fan, DisplayPort cable, hard disk drive (HDD), HDD data cable, HDD power cable, LCD panel with glass, left speaker, memory, right speaker, solid-state drive (SSD)/Flash storage card, stand, WiFi/Bluetooth antenna(s)
Quick Check
Symptoms
- Computer does not turn on
- Computer does not turn off
- No image on internal or external displays
- No startup sound
- No sounds from fan or hard drive (if hard drive present)
- No Caps Lock LED when key is pressed on wired keyboard
- Non-operational
Note: Inform user that computer failures due to accidental damage are not covered. If applicable, discuss out-ofwarranty repair options.
Deep Dive
| Check | Result | Action | Code | Commodity | |
|---|---|---|---|---|---|
| The user may report that the computer will not turn off or the computer will not turn on (no power). | Will Not Turn Off Go to step | 22. | ${nodeText.yesSymptomCode} | ||
| 1. | Which issue is the user No Power | Go | to step 2. | ${nodeText.noSymptomCode} |
Table Caption: This table outlines troubleshooting steps for computer power issues, categorizing them by whether the computer won't turn off or won't turn on (no power), providing a corresponding action and a code for each scenario.
Quick Check
- Verify AC power source. 1.
- Disconnect all peripherals. 2.
- Verify user's power cord. 3.
- Determine whether computer is in power-on state by 4. checking for all of the following:
- Caps Lock LED on wired keyboard
- Fan spinning sound
- Startup sound
- Hard drive spin (if hard drive present)
- Display backlight on
- External display activity
- Thunderbolt disk mode operation
- Reset SMC using the procedure listed in article 5.
HT201295: Resetting the System Management Controller (SMC) on your Mac.
CAUTION: Be extremely careful when working inside the computer with power applied and the system energized. Avoid touching the logic board or power supply while the computer is plugged in. Always cover the power supply and logic board with power supply covers to protect yourself when working inside the computer.
Before removing any components, be sure to turn off computer, and unplug computer from AC mains by disconnecting both ends of its power cord. Ensure computer is completely disconnected from AC mains before proceeding.
For additional safety information and tips, refer to articles:
- TP833: iMac and Displays: Power Supply Cover Instructions
- TP820: iMac (27-inch): Safety
- TP914: iMac (21.5-inch): Safety
Table Caption: This table outlines troubleshooting steps for a computer that fails to power on, guiding the user through checks of power activity, the power cord, AC inlet, and electrical outlet.
Table Caption: This table outlines troubleshooting steps for a Mac power issue, guiding the user through SMC resets and hardware inspections, with actions and code references for each step.
**Table Caption: This table outlines troubleshooting steps for a computer that is not powering on, guiding the user through checking for power activity, isolating
