Aporte original por: da stumer ,
Beeping usually indicates bad RAM, and not waking up from sleep sounds like it could be caused by that as well. In order to access the RAM you need to take off the screen and access the logic board. Booting to Apple Diagnostics might be able to help diagnose the issue. If you still have AppleCare you might want to have Apple check it out, as opening it will void any warranty it does have.