Mac Desktops First Steps
Always perform the following steps before starting a repair:
- If replacing the logic board, turn off Find My Mac. Choose Apple Menu > System Settings > Apple Account. Select iCloud in the sidebar. Then deselect the Find My Mac checkbox. If you’re unable to access the Apple menu, continue performing the following steps. 
- If you were unable to turn off Find My Mac from the Apple menu, go to iCloud.com/find on a different device. Select All Devices. Select the device you want to remove. Then select Remove from Account. 
- Unplug the power cord from both the electrical outlet and the back of the device. Keep the power cord unplugged while the device is being repaired. 
- Disconnect all other cables from the device. 
- Clear and clean your workspace. 
- Put on an ESD wrist strap and attach it to a properly grounded ESD mat. 
Caution
ESD (electrostatic discharge, or the release of static electricity) can damage electronic components.
Be aware of the following while performing a repair:
- The manual for this model may show images of other models, but the procedures are the same. Ensure that you use the correct tools for the model you’re repairing. 
- Take your time. Thoroughly read all instructions and alerts. 
- Magnetizing the screwdrivers will make it easier to work with small screws. 
- Use only Kapton tape to secure cables and keep them out of the way when removing and reinstalling parts. 
- The end of each flex cable must align with its connector. Press the end of each flex cable to its connector until it clicks to ensure that it’s secure.