The moment a Mac starts to behave abnormally, most people try to restart it once or twice, and if that doesn't help, they head straight to the service center. However, there is another solution that can save you not only a trip to the service center, but also a month-long wait for the claim to be processed. Apple uses the so-called NVRAM (formerly PRAM) and the SMC controller in its computers. You can reset both of these units and it often happens that this not only solves the current problem, but even extends the battery life and especially older computers get a second wind, so to speak.
How to reset NVRAM
The first thing we reset if something doesn't seem right on our Mac is NVRAM (Non-Volatile Random-Access Memory), which is a small area of permanent memory that the Mac uses to store some settings that it needs quick access to. These are sound volume, display resolution, boot disk selection, time zone and the latest kernel panic information. The settings may vary depending on the Mac you use and the accessories you connect to it. In principle, however, this reset can help you mainly if you have problems with the sound, the choice of the startup disk or with the display settings. If you have an older computer, this information is stored in PRAM (Parameter RAM). The procedure for resetting PRAM is exactly the same as for resetting NVRAM.
The first thing you need to do is turn off your Mac and then turn it back on. Immediately after pressing the power button on your Mac, press four keys at the same time: Alt, Command, P a R. Hold them down for approximately twenty seconds; during this time it may appear that the Mac is restarting. Then release the keys after twenty seconds, or if your Mac makes a sound when starting, you can release them as soon as this sound is heard. After you release the keys, the computer boots classically with the fact that your NVRAM or PRAM is reset. In the system settings, you will need to change the sound volume, display resolution or the choice of startup disk and time zone.
How to reset SMC
If resetting the NVRAM didn't help, then it's important to reset the SMC as well, and frankly almost everyone I know whenever they reset one thing, they reset the other as well. In general, MacBooks and desktop computers differ in what the controller takes care of in which case and what the NVRAM memory takes care of, so it is better to reset both. The following list of issues that can be resolved by resetting the SMC comes directly from Apple's website:
- The computer's fans run at high speeds, even if the computer is not particularly busy and is properly ventilated.
- The keyboard backlight is not working properly.
- The status light (SIL), if present, is not working properly.
- Battery health indicators on a Mac laptop with a non-removable battery, if available, do not work correctly.
- The backlight of the display does not respond correctly to the change in ambient lighting.
- Mac does not respond to pressing the power button.
- The Mac notebook does not respond properly to closing or opening the lid.
- Mac goes to sleep or shuts down unexpectedly.
- The battery is not charging properly.
- The MagSafe power adapter LED, if present, does not indicate proper activity.
- The Mac is running unusually slowly, even if the processor is not particularly busy.
- A computer that supports target display mode does not switch to or from target display mode correctly, or switches to target display mode at unexpected times.
- Mac Pro (Late 2013) input and output port lighting does not turn on when you move the computer.
- Turn off your MacBook
- On the built-in keyboard, hold Shift-Ctrl-Alt on the left side of the keyboard while simultaneously pressing the power button. Press and hold all keys and the power button for 10 seconds
- Release all keys
- Press the power button again to turn on the MacBook
If you want to perform an SMC reset on a desktop computer, i.e. an iMac, Mac mini, Mac Pro or Xserver, follow these steps:
- Turn off your Mac
- Unplug the power cord
- Wait 15 seconds
- Reconnect the power cord
- Wait five seconds, then turn on your Mac
Just a note, there will be more in NVRAM/PRAM. With MBP 2008, the graphics card, backlight, etc. will also change. At the same time, even with the MBA, I always liked the backlight of the keyboard.
Practically in the 10 years that I have been using HW from Apple, I have done the SMC reset only once, the NVRAM/PRAM reset and clearing the cache using the Onyx / cache cleaner program always helped me, and of course correcting the permissions on the system files, which is no longer necessary today.
Did you only do it once and it "always helped you"?
it just works...lol...not even by mistake with apple these days
on the other hand, Windows doesn't even remember the last time I had a problem :)
Me when I happen to have a problem. He hasn't been in a long time. I remove the back cover and disconnect the battery. I reconnect and the problem is gone. On that occasion, with the battery disconnected, I will also clean it a little carefully. On dry. A special screwdriver is required for disassembly. I don't even have the notebook screwed down, just taped on two opposite sides. I have a laptop that was spilled with wine and was ruined. After cleaning and buying a new battery, it works perfectly fine.
Both of the above reset procedures do not work for me. Yes, the fan spins like crazy. . . Why does such a problem even happen?
You probably have something with the battery. After replacing the battery, my fans always work normally
It helped! Thanks!