The process outlined in the article you linked to is incorrect for your MacBook Pro.
For your particular model of MacBook Pro, you really should follow this process to reset the SMC:
- Shut down your Mac
- Unplug the power cable from your Mac
- For 10 seconds, press and hold at the same time the shiftcontroloption keys (on the left side of the built-in keyboard) and the power button
- After 10 seconds let go of all keys and the power button
- Plug in the power cable
- Turn your Mac back on with the power button.
I would try doing this and testing to see if that resolves your issues.
Since resetting the SMC didn't resolve the issue, it's also worth trying a few more troubleshooting steps.
Resetting the NVRAM
Older Macs had what's called Parameter RAM (PRAM), newer Macs use Non-Volatile Random-Access Memory (NVRAM). It may be worth you also resetting this. There's a couple of ways you can do this, but for your model I recommend the following steps:
- Shut down your machine. Yes, a full shut down, not just logging out.
- Press the power button and then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
- Hold those keys down until your Mac reboots again (i.e. a 2nd time) and you here the startup chime.
- Let go of the keys and let your Mac reboot normally.
Note: When you log back in you may need to readjust some of your system preferences (e.g. speaker volume, screen resolution, startup disk selection, time zone information, etc).
Now test the MBP for a change in its behaviour. If you're still experiencing problems, then try booting into Safe Mode.
Boot into Safe Mode
Follow these steps to boot your Mac into Safe Mode:
- Fully shut down your Mac
- Restart your Mac
- Immediately press the Shift key and keep it down
- Let go of the Shift key when you see the login window (NOTE: If you have FileVault enabled you may need to log in twice).
- Take a note of what happens (i.e. is the power indicator working, does it go to sleep when closing the lid, etc)
- Now exit Safe Mode by restarting your Mac as normal
- Test the MBP again to see if there's any change in its behaviour.
If the problem is still persistent in Safe Mode, then we should test your hardware with Apple Hardware Test.
Run Apple Hardware Test
Your model MBP uses Apple Hardware Test. To use this, follow these steps:
- Shut down your MacBook Pro
- Restart your MacBook Pro
- Press and hold the D key before the gray startup screen appears.
- After a while, Apple Hardware Test (AHT) will start.
- When prompted, select your language and click the right arrow.
- When the AHT console appears, you can choose to run Basic tests by clicking the Test button. However, I suggest you select the "Perform extended testing" checkbox before you click the Test button.
- Your test results will appear in the window in the bottom-right of the console.
Note 1: that the extended test will take some time. Take a note of the results and report back.
Note 2: If pressing and holding the D key at Step 3 doesn't work, start again at Step 1 and, at Step 3 press and hold both the OptionD keys instead. This will try and run diagnostics from the internet instead, so you will need to allow more time for it to complete.