Power Issue MacBook Pro Late 2011
Hello! My MacBook Pro 15" Late 2011 intermittently won't turn on unless power cord is plugged in. So, there are a few scenarios I have run into:
1) I try to wake my laptop with the power cord plugged in and it operates normally
2) I try to wake my laptop without the power cord, but utilizing the built-in battery, and it powers normally
3) I try to wake my laptop without the power cord, and the laptop won't turn on. When this happens, I do the SMC reset with the power cord NOT attached, and then it powers and then powers normally every time. It appears that an error message briefly pops up but it disappears too quickly to read it. (Between scenarios 2 and 3, 3 is the norm)
I have tried to run the hardware diagnostic test but it gives me an "unable to run diagnostics dec500 message".
Obviously, I want to try to figure out how to prevent the third scenario from happening. Any suggestions? Thanks!!!