Additionally, if you hear a sequence of startup tone rather than hearing it just once, you may also have some underlying issues that need to be looked at.Īpple notes in a support document that it’s normal to hear a single audible tone each time your Mac is turned on, but if you hear it more than once, it’s indicative of a hardware or software problem that needs immediate attention. If you don’t hear it, and your volume isn’t turned all the way down, you might have a reason to be concerned. This is known as the POST (Power On Self Test) and the single startup tone before each boot up means it passed the test. Hold them for 10 seconds.Despite the evolution over the years, the macOS startup tone remains a critical part of the boot up process to let you know that your Mac passed its boot up tests and that everything appears to be A-OK. After it shuts down, press the Shift, Control, and Option keys along with the on/off button at the same time.

Earlier MacBooks without a removable battery Hold down the on/off button for about 5 seconds.ģ. Earlier MacBooks with a removable battery

After it shuts down, press and hold the on/off button.Ģ.

Here is what Apple recommends for each system. The steps to reset the SMC on your computer will be different based on which model of MacBook you own. If your Mac shuts down unexpectedly, first boot it up and perform a full restart to make sure all the programs have a chance to close properly.

Fans running at high speeds, your computer working abnormally slowly or not recognizing external devices, and battery charging issues are all signs that an SMC reset is in order.īefore you go on to perform any operations, keep in mind that hard shutdowns are not healthy for your computer. Because it is such an integral part of the computer’s inner working, it can also be the cause of a wide range of problems. Things like button presses, battery management, and indicators as well as other low-level functions all run through the SMC. Intel-based Mac computers have a chip called the System Management Controller which governs many functions on the device.

Macbook pro 3 beeps without opening up