Press the power button on the back of your iMac
The power button on an iMac is located on the back of the machine, toward the bottom right corner. It is a small circular button that you press once. You will hear a startup sound — a chime or tone — within a few seconds, and the screen will light up.
If your iMac does not respond after pressing the button, check that the power cable is plugged firmly into both the back of the machine and the wall outlet. The cable should click into place. If the outlet itself is controlled by a power strip or surge protector, make sure that switch is turned on as well.
The startup process takes between 30 seconds and two minutes, depending on how long it has been since the machine last ran. During this time, you may see the Apple logo appear on the screen. Let the computer finish starting up — do not press the button again.
Key Takeaways
- The power button is a small circular button on the back of the iMac near the bottom right, and you press it once to start the machine.
- You will hear a startup sound and see the Apple logo appear on the screen within seconds of pressing the button.
- Startup takes 30 seconds to two minutes; the computer is working during this time and should not be interrupted.
- If the iMac does not start, check that the power cable is plugged in firmly at both the machine and the wall outlet.
What happens during startup
After you press the power button, the iMac runs through a series of checks and loads the operating system into memory. The screen may remain black for several seconds before the Apple logo appears. This is normal. You may also see a spinning gear or progress indicator on the screen.
Once the operating system has fully loaded, you will see the login screen. If you are the only user on the machine, it may log in automatically and take you directly to the desktop. If there are multiple user accounts, you will need to select your name and enter your password.
Logging in with your password
If the login screen appears, click on your user account name. A password field will open below it. Type your password and press Enter or click the arrow button to the right of the password field.
If you have forgotten your password, you can reset it using your Apple ID. Click the question mark icon on the login screen, and follow the prompts to verify your identity. This process requires internet access and may take several minutes.
Reaching the desktop
Once you have logged in, the iMac will load your desktop. You will see the menu bar at the top of the screen, the Dock (a row of process icons) usually at the bottom, and your desktop background. The desktop is now ready to use.
If you see a login screen but the computer is not responding to keyboard input, wait 10 to 15 seconds — the system may still be loading. If the keyboard or mouse is not working, try unplugging it and plugging it back in, or check that wireless devices have fresh batteries.
Troubleshooting if the iMac will not start
If you press the power button and nothing happens, first check the power cable. Unplug it from the wall outlet, wait 10 seconds, and plug it back in. Then press the power button again. If the machine still does not start, try a different wall outlet to rule out a problem with the power strip or outlet itself.
If the iMac starts but the screen remains black, the computer may be starting up but the display is not turning on. Wait two minutes. If the screen is still black, try pressing any key on the keyboard or moving the mouse — sometimes the display goes to sleep during startup and needs to be woken.
If you hear the startup sound and see the Apple logo but the machine freezes or restarts repeatedly, the operating system may be having trouble loading. In this case, hold down the power button for 10 seconds to force the machine to shut down, wait 30 seconds, and press the power button again to try starting fresh.
Using sleep mode instead of shutting down
You do not have to turn off your iMac every time you stop using it. You can put it to sleep by pressing the power button once and holding it for a moment until a menu appears, then selecting "Sleep." Alternatively, go to the Apple menu at the top left of the screen, select "Sleep," and the machine will go into low-power mode.
When your iMac is asleep, it uses very little electricity but wakes up when ready when you press a key or move the mouse. This is faster than a full shutdown and startup. To wake the machine from sleep, press any key on the keyboard or move the mouse.
Frequently Asked Questions
How long does it take an iMac to start up?
A typical startup takes 30 seconds to two minutes. Older machines or machines with many programs installed may take longer. If startup takes more than three minutes, the machine may be having trouble loading the operating system.
What if the power button does not light up?
The power button itself does not usually light up on an iMac. Instead, you will hear the startup sound and see the Apple logo on the screen. If you hear nothing and see nothing after pressing the button, the power cable is likely not connected properly or the outlet is off.
Can I turn on an iMac using the keyboard?
No. The iMac can only be turned on by pressing the physical power button on the back of the machine. Once the machine is on, you can use the keyboard to log in and control it, but the initial startup requires the power button.
Is it bad to turn off an iMac every day?
No. Turning off your iMac daily is not harmful to the machine. However, putting it to sleep uses less energy and is faster than a full shutdown and startup. Choose whichever method fits your routine.
What should I do if the iMac starts but will not show the login screen?
Wait two to three minutes — the machine may still be loading. If the screen remains black or frozen, try pressing any key on the keyboard or moving the mouse. If nothing appears after five minutes, hold the power button for 10 seconds to force a shutdown, then try starting again.