it is very hard to know if your raspberry pi issue is power related if you don't do what you can to make sure that power isn't an issue.

prior Pis didn't log when they had power issues, and current ones do, if they are able to.

on a Pi 2 A (I think) I had to hook up an oscilloscope to catch all the tiny power problems I was having, and only then realized what was happening. I was 100% sure I was delivering enough power. I was not. those symptoms were only visible without the scope as weird errors in the OS and running applications, and corrupted SD cards.