Apple iMac does not power on; Repair Guide:

iMac Repair Plano

Are you having problem with your iMac where you press the power button and the iMac does not turn on at all? Does it get stuck in a boot loop or just a black screen? Try to follow the steps below in order to diagnose your device to identify where the problem is coming from. And you will be back on your device in no time.

At any point while doing this, if you think you are not confident enough or you are worried that it is something major and you might mess it up even more, feel free to stop it at that point and take it to any certified technicians so that they can help you out.

We can never figure out on our own exactly what is wrong with the iMac and for all kind of problems there are different sets of solutions depending on the situation. Following is a step-by-step instructions in order to diagnose an iMac that is not turning on:

  1. Check and see if the iMac is receiving any power

This is a very easy and quick step that we can take in order to check if the device is receiving any power. From the wall outlet, power cable, and secure plug-in must be inspected thoroughly.

Also we have to be careful to not mix up the iMac cables that are used for iMacs before and after 2012 as they changed the sizes on the cable. Although it feels like it all fitted, the plug may not be inserted all the way down to the main power socket resulting in an iMac with no power.

2. Check for a Stuck Power Button

If the power button gets stuck, there is no way you can turn on the device. As time goes by, the power button might get stuck simply because it got old and it accumulated some dirt residue inside the area that it can no longer send a valid signal to the logic board and hence iMac won’t turn on.

Try and follow some simple steps if this is the case. Changing a power button by itself is a very rare case and most of the times, they just start working after you perform a simple cleaning routine.

  • Unplug the power cord
  • Put the iMac on a flat desk facing it down.
  • Apply couple drops of WD-40 to the button and let it sit for a while.
  • Try pressing the power button in order to release the dirt out of the button.
  • Wipe it clean with a paper towel.
  • If you can still see dirt and the power button is still stuck, try the steps as long as it gets all cleared out.

3. Check for any Faulty External Devices

Most of the times, it turns out to be the external devices that you connected which is drawing out more power than it needs. As a safety measure try to turn on the iMac after disconnecting all the attached accessories from the including printer cable, USB hub, external USB hard drive, etc.

4. Reset the SMC or T2 Chip

The SMC (System Management Controller) is the one which receives all the power button signals, start ups and manages the entire power on process. An SMC or System Management Controller Reset can fix various power related issues, such as a piece of hardware not functioning correctly. To reset the SMC, following steps can be performed:

  • Macbook 2009 through 2017
  1. Shut down the computer
  2. Disconnect the MagSafe power adapter and remove the battery.
  3. Press and hold the power button for 5 seconds and release it.
  4. Reconnect the battery and MagSafe adapter and turn on the computer.
  • Resetting SMC on portables with a battery that you should not remove on your own
  1. Shut down the computer.
  2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
  3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
  4. Release all the keys and the power button at the same time.
  5. Press the power button to turn on the computer.  
  • Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve
  1. Shut down the computer.
  2. Unplug the computer’s power cord.
  3. Wait fifteen seconds.
  4. Attach the computer’s power cord.
  5. Wait five seconds, then press the power button to turn on the computer.