kept rebooting itself several times whenever restart my MacBook Pro

Hi,

I am running into this problem very often. When trying to shut down my MacBook, and it never shut down successfully. Instead of shutting down completely, it pops up a message saying 'Your laptop is running into some problem and will reboot or you can hit enter now. Also, when trying to restart and I am also running into the same problem as above. I have to restart several times (at least 5 times) in order for it to launch the operating system properly. Also, I can not update whenever there's an update available. In order to run the software update, I need to reboot into the safe mode. Once the update is completed, then I need to restart it, but it will go through several times before it can launch the operating system properly. Any answers will be appreciated. Thanks so much in advance.

By the way, I have brought my laptop to Apple Store, and they ran the diagnostic, but could not find any problem, but they suspected that the logic board is bad.