Tones on Starting
Sometimes you'll turn your Mac on and it'll start beeping in a variety of patterns. Here’s a short list of what each beeping pattern means:
I just upgraded the RAM in my MacBook Pro (15' 2 GHz Intel Core i7 - early 2011 model) from two 2gb modules to two 4gb modules. Started up just fine and ran great for about 10 minutes. Then the screen froze and the computer started beeping. After some google searches I found that it is caused by either a) bad RAM or b) the RAM is inserted.
- 1 tone repeating every 5 seconds:
It has been correctly pointed by jack4rall that 3 beeps from `Dimension 4400' indicates that a failure occurred in the first 64 KB of memory. The suggested fix is to re-seat the memory modules. If the issue still persists remove the Video card from the machine and check with the old Video Card if it works. Jun 12, 2020 I recently upgraded my ram in a 2009 MacBook pro and when I turned it back on I started getting the 3 beeps with nothing on screen. Carried out a troubleshoot of ram and slots below. I reinstalled old ram in both slots and got 3 beeps and nothing on screen. Then only installed new ram in bottom slot leaving top slot free - laptop turned on. Macbook beeps 3 times Couple of days ago my macbook freezed and started beeping thrice, I imeediately google d it and found out it was bad RAM but couldn't find the cause. I want to buy a cheap RAM-'Transcend 4 GB DDR3 1600Mhz' but I am not sure that if macbook supports this.
When you start your Mac, it will automatically run system diagnostics. If you hear this pattern of beeping, it means that the Mac could not find any RAM installed. Either your computer's memory was removed or something is interfering with the system checkup.
- 3 successive tones followed by a 5-second pause:
This indicates that the Mac found RAM installed, but the memory failed to pass the data integrity check.
- 1 long tone if you hold down the power button:
This indicates that an EFI ROM update is in progress. This only happens on computers manufactured before 2012.
- A successive sequence of 3 long tones, 3 short tones, 3 long tones, etc.:
This means that your computer has detected an EFI ROM corruption and the computer is in EFI ROM recovery mode. Newer models recover automatically from a corrupted ROM. When this occurs, a progress bar appears on the screen during ROM recovery mode. While on this mode, you should not shut down or disturb the computer in any way until it completes the OS X boot.
For all of the tones on boot up we discuss above, you should look into contacting Apple tech support since they all indicate you’re your computer could be in dire need of maintenance.
User-Induced Tones
You can also cause your Mac to produce tones, usually with certain key combinations. These key combinations will initiate some operation upon start-up. These are a few of those combinations:
- Shift ⇧
Start up in safe mode.
- Option ⌥
Macbook Pro Beeps Three Times
Launch Startup Manager.
- C
Start up from a bootable CD, DVD, or USB drives. Half life 2 cinematic mod alyx skins.
- D
Start to either Apple Hardware Test or Apple Diagnostics, depending on which Mac you’re using.
- Option-D
Same above, but it will start these programs via the internet.
- N
Start up from a compatible NetBoot server.
- Option-N
Start up from a NetBoot server using the default boot image.
- Command-R
Macbook Pro Freezes Then Beeps 3 Times
Start up from OS X Recovery.
- Command-Option-R
Macbook Pro Beeps 3 Times Will Not Boot
Same as above, but using the internet.
Macbook Pro 3 Beeps Fix
These are some of the commands available at the start up and they will also produce unique sounds too.
Macbook Pro Beeping 3 Times How To Fix
It’s always important to know how to differentiate between user induced sounds and system sounds, as they can indicate a hardware or software failure on your Mac.