Then release the keys, wait a few seconds and turn on the laptop.Your repair repertoire should also include a couple of additional procedures that can occasionally eliminate otherwise inscrutable problemszapping the NVRAM and resetting the SMC.
2017 Book Air Smc Reset Mac Ailments AlwaysZap the NVRAM (or PRAM) Back in the day, the standard list of quick fixes for random Mac ailments always included zap the PRAM. The P in PRAM stood for parameter (the RAM was just RAMrandom access memory), and it referred to a small amount of special, battery-backed memory in every Mac that stored information the computer needed before it loaded the operating system. If the values in this memory got out of whack for one reason or another, your Mac might not start up correctly, or might exhibit any of numerous odd behaviors afterward. So you could press a key sequence at startup to reset (or zap) the PRAM, returning it to default, factory values. Modern Macs no longer use PRAM; they instead use something called NVRAM (NV for non-volatile). NVRAM serves approximately the same purpose as PRAM, but instead of storing a dozen or more pieces of information, it now contains just a few: your selected startup disk, speaker volume, screen resolution, time zone, andif your Mac has crashed recentlydetails of the last kernel panic. To reset your NVRAM, you use exactly the same procedure you once used to reset PRAM. Then let go and allow your Mac to continue starting normally. ![]() The most likely cause is that your Mac isnt registering the key presses due to wonkiness with a USB device. Disconnect all USB devices (except your keyboard, if its a wired keyboard), hold the power button down until the Mac shuts off completely, and then press it again and immediately hold down Command-Option-P-R. ![]() If youre able to reset the NVRAM successfully with the wired keyboard, you can disconnect it and go back to your normal Bluetooth keyboard. Reset the SMC Yet another component of your Macs hardware that stores crucial settings is the System Management Controller (SMC), a circuit that deals with power management, temperature monitoring and fan control, status lights, keyboard backlights, and a few other components. If your SMC becomes confused, you could experience problems like excessive fan noise, slow performance even though Activity Monitor doesnt show the CPU being overtaxed, apps that take forever to launch, batteries that dont charge correctly, problems with sleep or wake, and so on. You can see a longer list on this Apple support page.) As with zapping the NVRAM, resetting the SMC to factory defaults may resolve these problems. Apple says you shouldnt reset the SMC without first trying other troubleshooting tasks, such as force-quitting problematic apps and restarting your Mac. However, Apple doesnt mention any negative consequences of resetting the SMC, nor any way to determine for sure if the SMC is glitchy without resetting it and noticing that the problem went away. After that, the procedure varies depending on the type of Mac you have. Press and hold the power button for 10 seconds, then release it. After a few seconds, press the power button to turn on your Mac. On the laptop keyboard, press and hold Control-Option-Shift (your Mac might turn on). Hold these keys for 7 seconds, then press and hold the power button. If your Mac is on, it will turn off while you hold down the keys for another 7 seconds.
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