Power Issue MacBook Pro Late 2011

[jmmtennis91]

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!!!

 

[Sedulous]

Problem only manifests when waking from sleep on battery? Is it simply failing to wake or does it power off when wake is attempted?

My best guess is seems like a power state issue. SMC might not be sending power_ok or pm_sleep signal depending on behavior.

 

[jmmtennis91]

Yes, it seems to only have an issue when waking from the battery. When I lift/open my laptop, it does not wake when on battery alone unless I do the SMC reset. Then it operates absolutely perfectly on the battery. Is there anything I can do to test your theory? Not sure how to fix the sending power_ok or pm_sleep signal. Thanks for the reply!

 

[MC6800]

That brief error message might be found in the Console. You can type "wake" in its search box to help find it.

 

[Sedulous]

Yes, it seems to only have an issue when waking from the battery. When I lift/open my laptop, it does not wake when on battery alone unless I do the SMC reset. Then it operates absolutely perfectly on the battery. Is there anything I can do to test your theory? Not sure how to fix the sending power_ok or pm_sleep signal. Thanks for the reply!

If I were right (and that is a big “if”) this is likely not something most people would be comfortable doing. It involves opening computer and measuring voltages on small resistors.