Contribution d'origine par : Dan ,
Three beeps is a memory error! Reference here: [https://support.apple.com/en-us/HT202768|If your Mac beeps during startup] Reference this [https://support.apple.com/en-us/HT201165|MacBook Pro: How to remove or install memory]. Find your system and check to make sure your modules are the correct ones for your system. You may need to get a fresh set to test your system.