Diagnosing the Issue
Before attempting to revive a dead Mac, it’s important to diagnose the underlying issue. A Mac can fail to turn on for a variety of reasons – it could be a software issue, a hardware problem, or even just a drained battery. Here are some steps to help determine why your Mac won’t start up:
Check connections and power source
First, check that all the cables are properly connected and the power cable is plugged into a working outlet. If you’re using a laptop, try disconnecting the battery and power cable then holding down the power button for 10 seconds before reconnecting everything. This resets the SMC which can fix power issues.
Attempt safe mode
If your Mac gets stuck during start up or you see a prohibited symbol, try starting in safe mode. To do this, turn on your Mac and immediately press and hold the Shift key. This launches a basic version of macOS with only essential components enabled. If your Mac can start up in safe mode, it indicates the core system is likely OK and the issue is related to third-party software.
Run Apple Hardware Test
The Apple Hardware Test can diagnose hardware failures like bad RAM or a faulty hard drive. Restart your Mac and press and hold the D key – this will launch the hardware test. Allow it to complete – it will report any issues it detects which can help identify hardware faults preventing start up.
Reset NVRAM and SMC
Resetting the NVRAM and SMC can fix start up issues related to these components. The NVRAM stores info like screen resolution and SMC handles power management. Refer to Apple’s guides for the correct reset process for your specific Mac model.
Check for water damage or corrosion
Liquid getting into a Mac can short circuit components and prevent powering on. Carefully inspect the chassis and ports for any signs of water damage or corrosion. Allow to fully dry if wet before attempting to power on.
Trying to Boot from a Recovery Drive
If you cannot get your Mac to turn on at all, creating a bootable recovery drive on an external hard drive or USB stick can be used to start up the computer and potentially repair the drive.
Create a recovery drive
On a working Mac, you can create a recovery drive in System Preferences > Recovery. Alternatively, download the macOS recovery disk image from Apple and format an 8GB+ drive to make it bootable.
Connect recovery drive and boot from it
With the recovery drive connected, turn on your non-functioning Mac and immediately press and hold Command + R keys. This should allow boot up from the recovery disk.
Run Disk Utility and Reset NVRAM
Once booted from the recovery, open Disk Utility and check for errors on your main drive. You can also try resetting the NVRAM from the recovery. If successful, you may be able to boot normally again.
If other options fail, you can reinstall a fresh copy of macOS from the recovery drive. Ensure you backup any needed data first. This can resolve software issues preventing start up.
Using Target Disk Mode to Access Files
If you need to retrieve files from a Mac that won’t boot, target disk mode allows the drive to be accessed from another Mac.
Connect non-functioning Mac to a working one
Use a Thunderbolt or FireWire cable to connect your shut down, non-working Mac to a functioning host Mac.
Boot into target disk mode
Restart the non-working Mac and immediately hold down the T key. This boots it into target disk mode with the drive accessible as an external disk to the host Mac.
Copy needed files to host Mac
The host Mac can now access the start up disk of the target Mac allowing you to copy important documents, photos, etc. Save anything critical before proceeding with troubleshooting.
Exit target disk mode and disconnect cable
Once file transfer is complete, eject the target Mac disk on the host and power down the target Mac to exit target mode. Disconnect the cable and your Mac will boot normally again.
Troubleshooting Mac Hardware Issues
If you’ve narrowed the issue down to a hardware failure, here are some components to check:
Faulty RAM is a common cause of start up crashes or freezes. Try reseating the RAM modules and running the hardware test (holding D on boot) to check for errors. Test each stick one at a time in each slot to isolate failures.
A corrupted drive can prevent boot up. The recovery disk can run Disk Utility to check for and repair drive errors. If not repairable, the drive may need replacement.
Faults on the logic board can stop a Mac powering on entirely. Check for any signs of liquid damage or failed components. Logic board repair or replacement is suggested if diagnosed as the issue.
|RAM||Crash on boot, freezes||Reseat/replace RAM|
|Hard drive||Corrupted, won’t mount||Repair/replace drive|
|Logic board||No power on||Repair/replace board|
Failed components like display or fans
If specific components like the display, keyboard, or fans are malfunctioning, these can often be repaired or replaced independently without needing a new logic board.
Seeking Professional Repair
For Macs with hardware issues that you are unable to resolve yourself, seek help from a professional Mac repair technician. Some troubleshooting tips when utilizing repair shops:
Find an Apple Authorized Service Provider
Apple Authorized Service Providers are certified to perform Mac repairs per Apple standards. This gives the highest chance of quality repair.
Ask about pricing upfront
Get a quote for parts and labor costs before proceeding with repair. Mac logic boards in particular can be expensive to replace.
Inquire about data backup
Ask if the service will back up your data before working on the Mac. You ideally want to avoid data loss.
Get a detailed diagnosis
The repair center should provide a breakdown of identified issues and failed parts/causes prior to repair.
Request a warranty
Reputable repair shops will warranty their parts and labor for a period of time after the repair is completed.
Reviving a dead Mac generally requires systematic troubleshooting to identify and resolve the underlying issue. Try the various steps outlined here to diagnose hardware versus software faults impairing start up and functionality. For advanced issues, leverage the benefits of a professional Mac repair service. With persistence and care, even a dead Mac can often be brought back to life.