iMac Won't Turn On? What to Check and How to Save Your Files

When an iMac won’t turn on, the cause usually falls into one of three groups: no power reaching it, a power system that needs resetting, or a display or internal part that’s failed while the computer underneath still runs. Because an iMac is a computer built into a screen, a dead display and a dead computer look the same from the front. The steps below help you tell them apart, and explain how the drive inside your iMac, whether a hard drive, a Fusion Drive, or soldered Apple silicon storage, affects getting your files back.

iMac won’t turn on: check the power basics

1. Plug the iMac directly into a wall outlet you know works. Skip the surge strip or UPS for now; they fail more often than people expect.
2. Check the cable at the back. On Intel iMacs, the power cord should be pushed fully into the socket on the back; it can work loose. On the 24-inch Apple silicon iMac, the magnetic connector should click into place on the back, and the power adapter brick must be plugged into the wall.
3. Press the power button firmly. It’s on the back of the iMac, behind the lower-left corner as you face the screen. Press it once; don’t hold it.
4. Disconnect accessories: external drives, hubs, and docks.

Do a power reset

A power reset clears the power controller on Intel iMacs (Apple calls this resetting the SMC) and gives Apple silicon iMacs a full cold start:

1. Shut down if it’s on, then unplug the power cord from the wall or the back of the iMac.
2. Wait at least 15 seconds; 30 seconds doesn’t hurt.
3. Plug it back in and wait about 5 seconds.
4. Press the power button.

Apple’s support pages describe the exact procedure for each model, but the unplug-and-wait method is the same for nearly every iMac.

Look and listen for signs of life

Press the power button and pay attention to:

• A startup sound. Many iMacs play a chime when they start.
• Fan noise or a hard drive spinning up. On older iMacs with a hard drive, you may hear it spin and seek.
• A status light. Some older iMacs have a small white light on the front; the Apple silicon models don’t.
• A very faint image. Shine a flashlight at the screen in a dark room. If you can see a dim desktop or login screen, the display’s backlight has failed but the computer is running.

Any of these means the iMac has power and the problem is the display, graphics, or startup, not the power supply.

Test with an external display

Many iMacs from the last decade or so can drive an external monitor through a Thunderbolt, Mini DisplayPort, or USB-C port. Connect one and start the iMac. If a picture appears on the external monitor, the iMac’s built-in display has failed, and you can back up your files right away while it still runs.

When the iMac starts but doesn’t finish

If you get a gray screen with a flashing folder and question mark, the iMac can’t find its startup disk; see Mac folder with a question mark. If it hangs on the Apple logo or a progress bar, see Mac stuck on the Apple logo. On iMacs with a hard drive or Fusion Drive, these symptoms often mean the drive is failing.

If it starts at all, run Apple Diagnostics: on Intel iMacs, hold D while starting up; on Apple silicon, hold the power button until startup options appear, then press Command + D.

Your data depends on what’s inside your iMac

Hard drives and Fusion Drives (many 2012 to 2019 models)

Many iMacs from this era shipped with a spinning hard drive, often a slow 5400 rpm model in base 21.5-inch configurations, or a Fusion Drive, which combines a small SSD with a hard drive. These hard drives are the most common reason an older iMac stops starting.

• A Fusion Drive spreads your data across both the SSD and the hard drive. Recovering from only one gives you an incomplete set of files, so both parts have to be read together.
• A failing hard drive gets worse with every startup attempt. If you hear clicking, or the iMac keeps hanging during startup, stop powering it on.
• Since 2012, the iMac’s glass is glued to the case. Opening it means cutting adhesive near a fragile display, so it’s not a casual DIY job.

T2 and Apple silicon iMacs

The iMac Pro and the 2020 27-inch iMac use Apple’s T2 chip, and every Apple silicon iMac (24-inch, 2021 and later) has storage soldered to the logic board and encrypted by the Apple chip. Removing parts won’t get you the data; it can only be read through that iMac’s own board, with your login password.

If it still starts: copy the files off

If the iMac powers on but you can’t use it normally, it can share its disk with another Mac:

• Target Disk Mode (Intel iMacs): hold T at startup and connect to another Mac with a Thunderbolt or USB-C cable.
• Share Disk (Apple silicon): start up in macOS Recovery, choose Utilities, then Share Disk, and connect to another Mac.

More detail is in how to get files off a dead laptop or computer. Once you’ve recovered, set up a backup that follows the 3-2-1 backup rule. See also our Apple data recovery page.

The bottom line

When an iMac won’t turn on, plug it straight into the wall, reseat the power cable, do a 15 to 30 second unplugged power reset, and look and listen for signs that it’s actually running. An external display tells you whether the screen is the problem. On older iMacs, the hard drive or Fusion Drive is often the real failure; on Apple silicon iMacs, the data can only come off through the original board.

Our Mac data recovery service recovers data from dead iMacs, failed Fusion Drives, and soldered Apple silicon storage for one flat $1,200 price for a single device. Shipping is free and prepaid, and you pay nothing unless the recovery succeeds.