Is it safe to give my MacBook to a service center with my data on it?
Often a service center need access to the Mac to verify if the problems are solved. You can do a few things.


The most important thing first. Make a backup from all your data before you give your Mac to the service center.
Turn on FileVault. It encrypts the harddisk.
Make a second user and provide these details to the service center so they can test.