Apple Mac电脑在可靠性方面通常坚如磐石，但有时你按下电源按钮，除了黑屏什么都没有！也许您的Mac已打开，但您无法将其引导至操作系统。如果您的Mac无法打开或启动到macOS，您可以按照以下步骤重新开始工作。
1. 执行强制重启
Mac(Macs)没有连接或断开电源流的物理电源开关。它只是一个向计算机发送指令以关闭、打开或进入睡眠状态的按钮。
Mac(Macs)有时会卡在开机信号被忽略的情况下，但是在大多数情况下，内置的故障保护应该可以让系统打开（或关闭）。您所要做的就是按住电源按钮至少 10 秒钟，然后根据当前状态强制关闭或打开Mac 。
假设(Suppose)您看到Apple标志。恭喜！您的Mac现已开机，但您可能仍会遇到其他启动问题。
2.了解启动错误图标
如果您的Mac开机但没有启动到 macOS 的登录屏幕，您可能遇到了某种问题。大多数情况下，您会看到一个错误图标，该图标指的是特定问题。
如果您看到一个带有一条线的圆圈，那么您正在查看禁止符号。这意味着您的Mac(Mac)尝试从中引导的硬盘上的 macOS 版本具有与相关Mac不兼容的 macOS 版本。这通常发生在您更换硬盘驱动器或安装了Mac错误地尝试启动的第二个驱动器时。
问号表示您的硬盘上没有 macOS，或者您的Mac根本看不到它。检查硬盘驱动器是否正确连接（如果适用）或查看您的启动磁盘首选项(Startup Disk Preferences)，我们将在下面介绍。
如果您看到锁定图标，则表示此Mac设置了固件密码。只有在您尝试使用外部驱动器启动时，您才会看到这一点。您必须询问设置密码的人为您输入密码或告诉您密码是什么。同样，您可能会看到系统锁定PIN码，这意味着Mac已被远程锁定并需要其密码。
3. 尝试以安全模式启动(Safe Mode)Mac
如果您的Mac(Mac)开机但没有完成启动以登录或桌面，您可以启动一个特殊的 macOS安全模式。(Safe Mode)安全模式(Safe Mode)是 macOS 中的一种受限模式，仅加载基本要素。使用Mac实用程序对系统进行故障排除或将Time Machine备份恢复到计算机正常工作时会很有帮助。您还可以删除任何可能导致问题的应用程序。
激活安全模式(Safe Mode)还会自动清除 macOS 缓存，因此您可能无需做任何事情来解决您的问题。只需(Just)在进入安全模式后重新启动您的Mac，如果问题与缓存相关，它应该会再次运行。
启动到安全模式(Safe Mode)会有所不同，具体取决于您是否拥有新的Apple Silicon Mac(Apple Silicon Macs)之一。
对于英特尔 Mac：
- 打开你的 Mac。
- 按住(Hold the) Shift 键(Shift key)。应出现Apple标志。继续握着钥匙。
- 当您看到登录屏幕时，您可以松开 Shift 键(release the Shift key)。
对于 Apple Silicon Mac：
- 打开 Mac 并按住 Shift 键(hold the Shift key)。
- 按住Shift键，直到出现启动磁盘选择菜单(startup disk selection menu)。
- 选择正确的启动盘(startup disk)，然后按住 Shift(hold Shift)。
- 现在选择Continue in Safe Mode。
您会知道您处于安全模式(Mode)，因为它会在菜单栏屏幕的右上角显示。
4.使用磁盘工具(Utility)修复您的启动盘(Startup Disk)
只需使用 macOS恢复(Recovery)功能即可解决许多启动问题。按住电源按钮强制关闭Mac以访问(Mac)恢复菜单(Recovery Menu)。
接下来，打开您的Intel Mac并立即按住 Command 和 R 键(hold Command and the R key)以启动到恢复(Recovery)菜单。如果您使用的是Apple Silicon Mac，只需在笔记本电脑关闭的情况下按住电源按钮，(press and hold the power button with the laptop off)直到您看到菜单。
然后选择使用磁盘工具修复您的启动磁盘(Use Disk Utility to repair your startup disk)选项。该实用程序将尝试使用其急救(First Aid)功能修复发现的任何错误，然后在重新启动后，一切都有望恢复正常。如果失败，您可能需要重新安装 macOS(reinstall macOS)。
5.确保在启动磁盘(Startup Disk)首选项中选择了正确的启动磁盘(Correct Boot Disk)
如果您的Mac尝试从错误的驱动器启动，您需要打开“启动磁盘首选项”(Startup Disk Preferences)菜单并仔细检查设置是否正确。
- 确保您的 Mac 已关闭。
- 在 Intel Mac 上，在 Mac 启动时按住Options 键。(Options key)
- 按住Apple Silicon Mac上的电源按钮(power button)，直到看到Loading Startup Options。
- 查看可能的启动磁盘的选择并选择正确的启动磁盘。
当您从外部驱动器启动 macOS(boot macOS from an external drive)时，这也很有用。
6. 给你的电池充电！
如果您在MacBook上遇到此问题，您首先需要将其连接到电源并确保电池中有足够(enough charge)的电量来启动系统。如果您的Macbook很长时间没有充电，则电池电压可能已经下降到足以阻止启动的程度。
如果您在连接电源时看到弹出充电符号，那么您就可以开始了。给它一点时间，然后再试一次。如果屏幕上没有弹出任何内容，请不要绝望。给它半个小时左右的时间，如果您仍然没有从系统得到任何响应，请继续执行其他故障排除步骤。
7. 检查和测试您的充电器(Test Your Charger)和电源线(Power Cable)
对于MacBook (MacBooks)Air(MacBook Air)或MacBook Pro等MacBook ，使用USB-C线缆和充电器进行充电。在出现磨损和损坏的连接器之前，我们曾遇到过Apple电缆的问题，因此请检查您的电源线以确保它仍然是一体的。
使用其他 USB-C 设备测试您的MacBook充电器和数据线（或在您的(MacBook)Mac上使用其他充电器和数据线）以确认它们工作正常。
8. 检查你的显示器连接
如果您使用的Mac没有内置显示器（如Mac Mini），请确保您的显示器已打开、插入并正常工作。您的Mac(Mac)可能根本没有任何问题，只是Mac和出现问题的显示器之间存在问题。
即使您的MacBook或 iMac 带有集成屏幕，也请尝试将其连接到外部显示器，以防实际问题是您的内置显示器已死！
9. 尝试不同的 Thunderbolt 端口
MacBook 可以从任何Thunderbolt端口充电。如果出现问题，请尝试与您通常使用的端口不同的端口。如果您的MacBook型号在计算机的左右两侧都有端口，请插入两侧的电源线，因为每组端口共享一个独立的控制器。
如果您的某个端口已损坏，您仍然需要将Mac送去检查和维修，但至少如果您可以启动它，您就有机会备份您的数据。
10. 移除您的 USB-C扩展坞(Dock)和外围设备
如果您首先通过 USB-C 扩展坞或适配器为Mac Book 供电，请从等式中移除扩展坞，因为它可能出现故障并阻止电源进入Mac。如果您的Mac在卸下扩展坞后仍无法启动，那可能不是问题所在。
除了扩展坞之外，移除您在操作Mac时并非绝对需要的其他外围设备，以确保 100% 确保它不是您连接的小工具之一导致问题。
11. 重置 PRAM & SMC
PRAM或参数 RAM是(Parameter RAM)Mac存储控制设置的存储区域。PRAM类似于NVRAM（非易失性RAM），即使在关闭时也能保留信息。如果该信息已损坏或不正确，则可能会阻止您的系统启动。
系统管理控制器(System Management Controller)是Mac的子系统，用于控制关键系统，例如冷却、电源管理、电池管理、视频模式切换和其他一些关键功能。如果SMC因某种原因冻结，您的Mac将无法启动或显示生命迹象。
好消息是，有一些方法可以在您的Mac上重置(Mac)SMC功能和PRAM设置。前往如何在 Mac 上重置 PRAM 和 SMC(How To Reset PRAM & SMC On Your Mac)以(Head)获取更多信息。
12.使用恢复模式(Recovery Mode)重新安装(Reinstall)macOS
如果您的Mac开机但未启动进入 macOS，您可以使用恢复菜单修复问题或重新安装 macOS(Reinstall macOS)。请注意，您可能会丢失存储在本地磁盘上的所有用户数据。这就是为什么最好将所有最重要的数据存储在 iCloud 或其他云存储服务中。在遇到麻烦之前，您还应该设置Time Machine驱动器。(Time Machine)
我们提供了一些指南，可帮助您重置Mac以拥有全新且正常工作的操作系统。首先(First)，查看如何在没有密码的情况下重新格式化 MacBook(How To Reformat Your MacBook Without a Password)，尤其是“重新安装 macOS”部分。如果您的Mac非常混乱以至于您无法从内部驱动器恢复 macOS 的新副本，请查看如何在 USB 记忆棒上制作 macOS 安装程序(How To Make a macOS Installer On a USB Stick)。
13. 取出电池
一些较旧的MacBook型号仍然有可拆卸电池。如果您仍在使用这些Macbook(Macbooks)之一，您可以选择卸下电池，然后按住电源按钮以使任何剩余电量消散。然后将电池放回原处并尝试再次启动您的Mac。
14. 重新安装您的固件
在极少数情况下，当您的系统在固件更新期间断电或因其他原因被中断时，它可能会损坏。这实际上会将您的Mac变成镇纸，但并没有丢失！
只要您拥有Apple Silicon Mac（如M1 Macs）或配备 T2 安全芯片的Intel Mac，您就可以使用第二台连接互联网的Mac和Apple Configurator App来恢复死机Mac的固件。当然，您需要一根USB数据线来连接这两个设备。Thunderbolt 3 电缆不起作用。
如果您无法访问第二台Mac，您可以在维修店（包括Apple官方商店）进行固件恢复。Intel和Apple Silicon Macs的流程略有不同，但一般流程如下：
- Apple Configurator安装在正常工作的Mac上。
- 两台计算机使用USB电缆连接。
- 损坏的计算机使用特殊的组合键重新启动。这因Mac的不同型号而异。
- Apple Configurator用于在工作的计算机上恢复或恢复有问题的计算机固件。
如果您的Mac在此过程后正常开机并启动，您应该可以无家可归了！
15. It's Dead Jim :私人维修(Private Repair)或保修更换(Warranty Replacement)
如果您的笔记本电脑或台式机Mac无论如何尝试都无法启动，那么是时候寻求专业帮助了。在现代Mac(Macs)中，当一个关键组件（例如电源）出现故障时，除非您能够访问查找和修复这些组件所需的复杂设备和知识，否则无法仅更换该组件。
如果您的Mac仍在保修期内，您的选择很简单。将您的Mac送至 Genius Bar的(Genius Bar)Apple 支持部门(Apple Support)进行评估，Apple将(Apple)解决问题或更换电脑。如果您的电脑已过保修期，您仍然可以付费让Apple维修它。然而，苹果(Apple)官方的维修费用通常非常高，以至于购买一台全新的电脑更便宜。
好消息是，也有很棒的私人电脑维修店专门修理Mac(Macs)，通常收费合理。您可能不得不将您的 mac 送走，但再次听到启动铃声是非常值得的！
15 Fixes You Can Try When Your Mac Won’t Turn On or Boot Up
Αpple Mac computers are υsually rock-solid when it comes to reliability, but sоmetimеs уou push thаt power button and get nothing but a black ѕcreen! Maybe your Mac switches on, but you can’t get it to boot into the OS. If you can’t get yоur Mac to turn on or boot into macOS, here are some steps you can follow to get back in business.
1. Perform a Forced Power Cycle
Macs don’t have a physical power switch that connects or disconnects power flow. It’s just a button that sends an instruction to the computer to turn off, turn on, or go to sleep.
Macs can sometimes get stuck in a situation where that power-on signal is ignored, but there’s a failsafe built in that should get the system to turn on (or shut down) in most cases. All you have to do is press and hold the power button for at least 10 seconds, after which the Mac will be forced to turn off or on, depending on its current state.
Suppose you see the Apple logo. Congratulations! Your Mac has now powered on, but you may still encounter additional startup problems.
2. Learn the Startup Error Icons
If your Mac turns on but doesn’t boot to macOS’s login screen, you’re probably experiencing some sort of problem. You’ll be shown an error icon that refers to specific problems most of the time.
You’re looking at the prohibitory symbol if you see a circle with a line through it. All this means is that the macOS version on the hard disk your Mac is trying to boot from has a version of macOS that’s not compatible with the Mac in question. This usually happens when you’ve swapped out hard drives or installed a second drive from which the Mac erroneously tries to boot.
A question mark means your hard disk doesn’t have macOS on it or that your Mac simply can’t see it. Check that the hard drive is correctly connected (if applicable) or review your Startup Disk Preferences, which we’ll cover below.
If you see a lock icon, it means that this Mac has a firmware password set. You’ll only see this if you’re trying to boot up using an external drive. You’ll have to ask whoever set the password to enter it for you or tell you what it is. Similarly, you may see a system lock PIN code, which means that the Mac has been remotely locked and needs its passcode.
3. Try to Start the Mac in Safe Mode
There’s a special macOS Safe Mode that you can boot into if your Mac turns on but doesn’t complete its startup all the way to login or the desktop. Safe Mode is a limited mode in macOS that only loads the bare essentials. Using Mac utilities to troubleshoot your system or restore a Time Machine backup to when your computer was working correctly is helpful. You can also delete any apps that may be causing issues.
Activating Safe Mode also automatically clears out macOS caches, so you might not have to do anything to fix your issue. Just reboot your Mac after being in safe mode, and if the problem was cache-related, it should work again.
Booting into Safe Mode is different depending on whether you have one of the new Apple Silicon Macs or not.
For Intel Macs:
- Turn on your Mac.
- Hold the Shift key. The Apple logo should appear. Keep holding the key.
- When you see the login screen, you may release the Shift key.
For Apple Silicon Macs:
- Turn on your Mac and hold the Shift key.
- Keep holding the Shift key until the startup disk selection menu appears.
- Choose the correct startup disk and then hold Shift.
- Now select Continue in Safe Mode.
You’ll know you’re in Safe Mode because it will say so in the top right of the screen on the menu bar.
4. Use Disk Utility to Repair Your Startup Disk
Many startup issues can be solved by simply using the macOS Recovery function. Press and hold the power button to force your Mac to turn off to access the Recovery Menu.
Next, turn your Intel Mac on and immediately press and hold Command and the R key to boot into the Recovery menu. If you’re using an Apple Silicon Mac, simply press and hold the power button with the laptop off until you see the menu.
Then choose the option Use Disk Utility to repair your startup disk. The utility will try to fix any errors found using its First Aid functionality, and then after a reboot, everything should hopefully be back to normal. If it fails, you may want to reinstall macOS.
5. Ensure the Correct Boot Disk is Selected in Startup Disk Preferences
If your Mac is trying to boot from the wrong drive, you’ll need to open the Startup Disk Preferences menu and double-check that the settings are correct.
- Make sure your Mac is off.
- On an Intel Mac, hold the Options key as the Mac starts up.
- Hold the power button in on an Apple Silicon Mac until you see Loading Startup Options.
- Look at the selection of possible startup disks and choose the correct one.
This is also useful when you boot macOS from an external drive.
6. Charge Your Battery!
If you’re having this issue on a MacBook, you’ll first want to connect it to power and make sure that there’s enough charge in the battery to start up the system. If your Macbook hasn’t been charged in a very long time, the battery voltage may have dropped low enough to prevent startup.
If you see the charging symbol pop up when you connect power, then you’re good to go. Just give it a little time and try again. If nothing pops up on the screen, don’t despair quite yet. Give it half an hour or so of being plugged in and if you still don’t get any response from the system, move on to other troubleshooting steps.
7. Inspect and Test Your Charger and Power Cable
With MacBooks such as the MacBook Air or MacBook Pro, charging happens using a USB-C cable and charger. We’ve experienced problems with Apple cables before exhibiting fraying and broken connectors before, so check your power cord to make sure it’s still in one piece.
Test your MacBook charger and cable with other USB-C devices (or use another charger and cable with your Mac) to confirm that they are working properly.
8. Check Your Monitor Connection
If you’re using a Mac that doesn’t have a built-in monitor (like the Mac Mini), make sure that your monitor is switched on, plugged in, and working properly. There may not be anything wrong with your Mac at all, simply something between the Mac and the monitor that’s gone wrong.
Even if you have a MacBook or iMac with an integrated screen, try hooking it up to an external display, in case the actual problem is that your built-in display is dead!
9. Try a Different Thunderbolt Port
MacBooks can charge from any of their Thunderbolt ports. Try a different one from the port you usually use if there’s something wrong with it. If you have a model of MacBook with ports on both the right and left sides of the computer, plug in the power cord on both sides since each set of ports shares an independent controller.
If one of your ports is dead, you’ll still need to send your Mac in for inspection and repair, but at least if you can get it to power on, you have an opportunity to make backups of your data.
10. Remove Your USB-C Dock and Peripherals
If you’re running your MacBook’s power through a USB-C dock or adapter first, remove the dock from the equation since it might be faulty and prevent power from getting to the Mac. If your Mac still doesn’t start up with the dock removed, that’s probably not the problem.
Apart from a dock, remove other peripherals you don’t strictly need to operate your Mac, to make 100% sure it’s not one of your attached gadgets causing an issue.
11. Reset the PRAM & SMC
PRAM or Parameter RAM is the storage area where your Mac stores control settings. PRAM is similar to NVRAM (nonvolatile RAM), which retains information even when turned off. If that information is corrupted or otherwise incorrect, it might prevent your system from starting up.
The System Management Controller is the subsystem of your Mac that controls crucial systems such as your cooling, power management, battery management, video mode switching, and a few other crucial functions. If the SMC has frozen up for some reason, your Mac won’t start up or show signs of life.
The good news is that there are ways to reset SMC functions and PRAM settings on your Mac. Head over to How To Reset PRAM & SMC On Your Mac for more information.
12. Reinstall macOS Using the Recovery Mode
If your Mac powers on but doesn’t boot into macOS, you can use the recovery menu to repair issues or Reinstall macOS. Just be aware that you’ll probably lose all of your user data stored on the local disk. This is why it’s a good idea to store all your most important data in iCloud or another cloud storage service. You should also set up a Time Machine drive before you ever run into trouble.
We have a few guides that will help you reset your Mac to have a fresh and working operating system. First, check out How To Reformat Your MacBook Without a Password, especially the “Reinstall macOS” section. If your Mac is so messed up that you can’t restore a fresh copy of macOS from the internal drive, check out How To Make a macOS Installer On a USB Stick.
13. Remove The Battery
Some older MacBook models still have removable batteries. If you’re still using one of these Macbooks, you have the option of removing the battery and then holding down the power button to allow any residual charge to dissipate. Then put the battery back and try to power up your Mac again.
14. Reinstall Your Firmware
On rare occasions, when your system has lost power during a firmware update, or it’s been otherwise interrupted, it may become corrupted. This will essentially turn your Mac into a paperweight, but all is not lost!
As long as you have an Apple Silicon Mac (like the M1 Macs) or an Intel Mac featuring the T2 security chip, you can use a second internet-connected Mac and the Apple Configurator App to restore the firmware of the dead Mac. Of course, you’ll need a USB cable to connect the two devices. Thunderbolt 3 cables won’t work.
If you can’t access a second Mac, you can have the firmware restoration done at a repair shop, including official Apple stores. The process for Intel and Apple Silicon Macs is slightly different, but the general process works like this:
- Apple Configurator is installed on the working Mac.
- The two computers are connected using a USB cable.
- The broken computer is restarted using a special key combination. This varies for different models of Mac.
- Apple Configurator is used on the working computer to either revive or restore the computer’s firmware that’s having issues.
If your Mac turns on and boots as usual after this process, you should be home-free!
15. It’s Dead Jim: Private Repair or Warranty Replacement
If your laptop or desktop Mac won’t turn on no matter what you try, it’s time to get professional help. In modern Macs, when a key component, such as the power supply, fails, there’s no way just to replace that one component unless you have access to the sophisticated equipment and knowledge needed to find and fix those components.
If your Mac is still under warranty, your choice is simple. Send your Mac in for evaluation by Apple Support at the Genius Bar and Apple will either fix the problem or replace the computer. If your computer is out of warranty, you can still have Apple repair it for a fee. However, official Apple repair costs are often so high that it’s cheaper to buy a whole new computer.
The good news is that there are also fantastic private computer repair shops that specialize in fixing Macs, usually for reasonable fees. You may have to send your mac away, but it’s well worth it to hear that startup chime again!
