You press the power button and your iMac will not start up. Or it turns on but gets stuck on the Apple logo, on a progress bar that goes no further, or you see a folder with a question mark. On an iMac that may be the power, the drive, macOS or the screen. This article explains step by step how to find out what is wrong, and what you can try yourself before having it checked.
Blue Apple repairs iMacs and MacBooks in Amsterdam. The steps below apply to the 24 inch iMac with an Apple chip and to Intel iMacs; where they differ, it says so.
Step 1: does the iMac get power?
- Try another socket, without a power strip.
- 24 inch iMac: the power adapter is separate. Check that the magnetic connector is properly on the iMac and that the cable from the adapter to the socket is firmly in.
- Intel iMac: the power supply is inside. Push the power cable at the back in firmly; it is sometimes loose.
If you hear nothing at all (no fan, no startup chime) and the screen stays dark, the iMac probably gets no power or the logic board does not start.
Step 2: is the screen the problem?
Do you hear the startup chime or the fan, but the screen stays black? Press Caps Lock: if the light comes on, the iMac is running. Shine a torch at an angle on the screen to see whether there is a faint picture. Then the screen or its backlight may be the problem, not the startup.
Step 3: force restart and SMC
- Hold the power button for ten seconds until everything is off.
- Intel iMac: unplug it, wait fifteen seconds, plug it back in, wait five seconds and turn the iMac on.
- 24 inch iMac: briefly disconnect the power adapter and reconnect it.
- Also disconnect all USB devices, drives and docks.
Step 4: stuck on the Apple logo or progress bar
If the iMac gets no further than the logo or half a progress bar, macOS may be damaged or the drive faltering. Try:
- Safe mode: see starting in safe mode.
- Recovery mode and First Aid: see opening Recovery mode and Disk Utility and First Aid.
- Reinstall macOS from Recovery mode; your files stay. See reinstalling macOS.
The hard drive in an Intel iMac
Many Intel iMacs have a hard drive or a Fusion Drive. It wears out after years. Typical signs: the iMac takes very long to start, gets stuck on the progress bar, or shows a folder with a question mark. Often First Aid finds errors, or Disk Utility does not see the drive at all. A new SSD solves that and makes the iMac much faster too. If you still can, make a backup first.
After an update
If the iMac no longer starts after a macOS update, try Recovery mode and reinstall macOS. On older iMacs going back to the previous version can help. See installing an older macOS.
When is it hardware?
- No sign of life at all, even on another socket.
- The iMac turns on and immediately off again.
- Repeated beeps at startup (on older iMacs a sign of a memory problem).
- Disk Utility no longer sees the drive.
What we do at Blue Apple in Amsterdam
We test the power supply, drive, memory and logic board, and look at what can be done with your data. You hear beforehand what it costs. Moving an iMac is awkward; see our pickup and delivery service. More about how we work: Mac and MacBook repair in Amsterdam.
Frequently asked questions
My iMac makes sound but the screen stays black. What is it?
Often the screen, display cable or backlight, sometimes the graphics chip. That needs testing.
Are my files gone if the iMac will not start?
Usually not. They can often still be recovered from the drive.
How long should startup take?
With an SSD half a minute to a minute. With an old hard drive it can take much longer; that is often a sign of wear.
