Mac models from early 2016 and earlier make a chime sound when they start up. Mac models from late 2016 and newer don't have a startup chime, with the exception of MacBook Air (13-inch, 2017).
If there's an issue with your Mac, it might make one of these tones when it starts up:
- One tone, repeating every five seconds: No RAM is installed. If you recently replaced or upgraded your computer's RAM, check to see if it was installed properly. If the issue continues, contact Apple Support.
- Three successive tones, then a five-second pause (repeating): RAM doesn't pass a data integrity check. If you recently replaced or upgraded your computer's RAM, check to see if it was installed properly. If the issue continues, contact Apple Support.
- One long tone while you hold down the power button: An EFI ROM update is in progress. This applies to Mac computers from before 2012.
- Three long tones, three short tones, three long tones: EFI ROM corruption is detected, and your Mac is in EFI ROM recovery mode. Newer computers automatically recover from a corrupted ROM; when this occurs, a progress bar appears on the screen during ROM recovery mode. Don't disturb your Mac while the ROM recovery takes place. When recovery is complete, your Mac restarts.
Memory Test For Mac Os X
Nov 08, 2018 Mac models from early 2016 and earlier make a chime sound when they start up. Mac models from late 2016 and newer don't have a startup chime, with the exception of MacBook Air (13-inch, 2017). If there's an issue with your Mac, it might make one of these tones when it starts up: One tone, repeating every five seconds: No RAM is installed. The version of Windows, Linux, or Mac being used is irrelevant for execution. However, you must use either Windows, Linux or Mac to create a bootable USB drive. System requirements.
Memory Test For Mac
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- Mac computers that have the Apple T2 Security Chip don't have EFI ROM tones.
- If you need to restore the EFI ROM on certain Mac computers produced before 2008, you'll need to use a Firmware Restoration CD to restore the EFI ROM. Search Apple Downloads for the right CD image for your computer.
- Pressing and holding keys on startup can make your Mac function in different ways. To learn more, see Startup key combinations for Mac.