This morning i woke up to a horror of one of my project Macbooks 13" (Late 2013 ) running macOS Big Sur 11.6.2 not detecting my full hd external display via the HDMI port.
I had previously disconnected it before heading for a meeting and the battery run dry the previous day then left it charging the whole night.
Out of frustration i abandoned it for the day but let the battery run to zero again after resetting the SMC.
To reset the the SMC, all you have to do is power the macbook off and Press Shift-Control-Option plus the power button for 10 Seconds then release and power on again.
On connecting the magsafe, powering it on, then connecting the HDMI cable again the external display was up and running as before.
Well i guess it hard something to do with the fact that the battery cannot be removed compared to the < =2012 Macbooks. Well its just my thinking.
Why? Because when resetting the SMC for earlier Mac Books, you have to remove the battery.