Troubleshoot Macbook Pro Shutdown?

I've recently been trying to troubleshoot this problem I've been having with my macbook, I would start my macbook and immediately see a progress bar, and soon after the laptop will turn off. I also tried running diagnostics but it would freeze, also tried installing a new HDD but will shutdown during the creation of a new HDD, and also tried replacing the RAM. But no luck, I try to keep fix the problem but stuck can someone help.