Hold the keys down until the computer restarts and you hear the startup sound for the second time.Ħ. It all started when i'm trying to downgrade from lion to snow leopard, I cleaned up my HD from disk utilities and it was a success after that i inserted an OS X snow leopard installation disk then when i rebooted my iMac it just shows grey screen then started to beep. Whenever you turn on your Mac, it will run diagnostic tests. Press and hold the Command-Option-P-R keys.ĥ. If your Mac wont turn on, and you instead hear beep sounds, there may be a hardware issue.

You will need to hold these keys down simultaneously in step 4.ģ. Locate the following keys on the keyboard: Command, Option, P, and R. Hold these keys and the power button for 10 seconds.ģ If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button.ĥ Press the power button again to turn on your Mac. How to fix MacBook beeping 3 times Try resetting the SMC Ģ After your Mac shuts down, press Shift-Control-Option on the left side of the built-in keyboard, then press the power button at the same time.

If the problem persists, visit an Apple professional immediately or contact Apple Support directly. You may have recently replaced or just upgraded the RAM memory on your MacBook Air or MacBook Pro computer and it was not installed properly. If your MacBook Air or MacBook Pro computer is broadcasting 3 successive beeps at intervals of approximately five seconds, it means that RAM memory did not pass the data integrity check. The beeping indicates that there is an issue with your notebook’s RAM.

Why MacBook beeping 3 times and won’t startup? Why MacBook beeping 3 times and won’t startup?.

Macbook pro 3 beeps wont start