Can't power on your laptop? Your issue could be related to the System Management Controller. If it is! Then this could be your solution to a non working macbook!
NOTE: This will only work if the original SMC reset did not work. If you have tried both the original SMC reset and this extended method and your computer still has not responded...then your problem lies elsewhere. This is simply just one method in getting your macbook to boot up, assuming the underlying issue is just residual power that needs to be reset or drained out. Other factors could be related to other hardware issues (i.e. ram, hdd, battery, charger, etc.).
Try doing an Extended SMC Reset:
1. Battery must be below 100% (leave the ac adapter unplugged for a couple hours (maybe even half the day) it will self discharge).
2. AC charge adapter must be plugged in
3. Amber steady light must be present
4. Hold down the left Shift+Control+Option keys and the Power key at the same time
5. Let go of all the keys
6. The led light on the charger will change from amber to green
7. QUICKLY PULL OUT and disconnect the charge cable before the green LED change back to amber
8. Your computer will automatically boot up now with the apple logo with the chime (If your computer is working perfectly before, it will not auto boot up FYI)
9. If your computer automatically shuts off again, please repeat these steps followed by a NVRAM / PRAM reset
10. Additionally, make sure your SMC software is up to date: support.apple....
After powering on this laptop, I realized her hard drive was full and unable to allow for updates. When this happens, ram is usually a place holder. And when that gets full, many applications tend to not open correctly. I would advise anyone to clear up and remove unneeded files, applications, transfer large media files to an external hard drive (if available), and to update their operating system to the latest version.