Your MacBook will make a power tone a few seconds after you connect it to its AC power adapter. The tone means that your MacBook recognized the power adapter.
If your MacBook is turned off when you connect the adapter, your keyboard and trackpad won’t become active until after you hear the tone. After the tone, you can press the power key to power up your MacBook.
It's best if you use the Apple AC power adapter that came with your computer. See these articles for more information on adapters:
- Identifying the right power adapter and power cord
- Using the USB-C port and adapters on your MacBook (Retina, 12-inch, Early 2015) and later
Get help starting your computer if it still won't turn on after you connect it to your power adapter.