[Solved] How to fix iMac, MacBook Air/Pro won't turn on/start up/boot?
I have a constant black screen on my MacBook Pro. Twice within the last six months I have inadvertently let the battery drain completely. Thinking this might be the problem, I replaced the battery and did an SMC reset. The power cord changed colors like it's supposed to and the battery seems to be charging but it still won't turn on. About a week after I replaced the battery it came on by itself. I was able to login , access files and mail and it seemed to work just fine. Foolishly, I logged out and turned it off and now I'm stuck with a black screen again. Any help would be greatly appreciated, thank you
Common scenarios of 'iMac/MacBook won't turn on'
Mac stuck on boot screen
iMac won't boot past Apple logo
MacBook stuck on loading screen
MacBook Air stuck on login screen
iMac stuck on black loading screen
MacBook Air won't turn on black screen
MacBook Pro won't turn on but its charging
Solution 1: Check the charging and power or reconnect the battery connector
Please check the charging and power for your iMac/MacBook when it won't turn on. Yes, you may think it is all working and nothing is wrong, but I fixed an older MacBook not turning on by switching to another charger.
1. Borrow a second charger from a friend and see if it works.
2. Make sure you are using the right charger for your iMac/MacBook.
3. Disconnect and reconnect the battery connector to see if iMac/MacBook can turn on.
Solution 2: Reset SMC
SMC is the System Management Controller which handles a lot of tasks (Such as power button, waking the MacBook Pro) for your Mac. If your MacBook Pro is new enough that you cannot remove the battery, please reset the SMC with following steps.
Step 1: Make sure your Mac is off, it isn't an issue if it won't turn on.
Step 2: Hold Shift + Control + Option and hold the power button for 10 seconds.
Step 3: After 10 seconds release the keys, wait a second, press the power button and see if the Mac computer can turn on.
Solution 3: Uninstall RAM or a Secondary Drive
If you opened up your Macbook Pro to upgrade RAM or add a new hard drive, that may be the problem. In this situation, uninstalling RAM/new hard drive and putting the old RAM/hard drive can solve the issue. Although tt is an annoying job, but it ss a good way to rule out something simple.
Solution 4: Run First Aid in recovery mode
After iMac/MacBook won't start up, Disk Utility built-in macOS recovery mode is a chance to repair the boot issue.
Step 1: Turn on Mac computer by pressing Power button.
Step 2: Press and hold Command+R keys immediately upon hearing the startup chime. Hold the keys until you see the Apple logo or a spinning globe.
Step 3: Select Disk Utility from macOS Utilities in Mac recovery mode.
Step 4: Select the corrupted Macintosh HD from the left panel of Disk Utility.
Step 5: Click "First Aid" button on the top of Disk Utility window.
Step 6: Click "Run" button to start the repair on the Macintosh HD.
Solution 5: Data recovery
After iMac/MacBook won't turn on, the important thing is the data stored in Macintosh HD. If the 'iMac/MacBook won't turn on' issue cannot be solved, you have to rescue the data from failed Mac computer.
M3 Mac Data Recovery is a professional Mac data recovery software which can recover deleted files emptied from Trash, recover data from formatted drive, recover data from unreadable drive, recover data from unmounted drive, recover data from corrupted drive, recover data from deleted/lost APFS partition, recover data from encrypted APFS drive, recover data after iMac/MacBook won't start up, etc.
Step 1: Download, install and launch M3 Mac Data Recovery software on another Mac computer.
Step 2: Click M3 Data Recovery on menu bar and select "Create Boot Drive".
Step 3: Insert a blank USB drive into Mac computer and start to create M3 Mac Data Recovery bootable media.
Step 4: Insert M3 Mac Data Recovery bootable media into the failed Mac computer and boot the Mac computer from M3 Mac Data Recovery bootable media.
Step 5: After M3 Mac Data Recovery is loaded, please select the failed Macintosh HD.
Step 6: M3 Mac Data Recovery software is scanning the data from the failed Macintosh HD.
Step 7: After the scan completes, please select the found files you want and then click Recover to save them.
Solution 6: Take your iMac/MacBook to Apple
If none of the above solutions helped, you will need to take your iMac, MacBook Air or MacBook Pro to an Apple Store or a local repair shop to start working on a DIY solution to fix your iMac/MacBook that won't turn on.