When your repair is complete and your Mac is successfully reassembled, you can re-enable the Auto Boot feature.

Power on your Mac and launch Terminal.

Copy and paste the following command (or type it exactly) into Terminal:

sudo nvram AutoBoot=%03

Press [return].

If you are prompted for an administrative password, type the password and press [return].

Your password will not be displayed in Terminal.

Alternatively, you may reset your Mac's NVRAM to re-enable Auto Boot.