Chosen Solution
I have a MacBook Pro 13’’ (mid 2012) with what seems to be a completely dead SMC: loud fan, not recognizing battery, unable to do SMC resets, turns on automatically when plugging charger, if I turn it off I have to unplug/plug it again to turn it back on. This means I could either have to replace the SMC or maybe even the whole logic board depending on what’s really the issue. But the problem is I’m unable to have it diagnosed or repaired where I’m at right now, so I have to wait a few weeks until I get back home. So I wanted to know if it was okay to just keep using it or if I run the risk of damaging it further?
Your system is limping! Besides a bad battery which you have removed. Your systems SMC logic has lost access to the sensors it depends on within the battery and for some reason the FaceTime (iSight) camera as well. So SMC will ramp up the fan and will lower the systems clocking so the system will be sluggish as SMC wants to make sure you don’t damage the CPU from overheating. Will it work this way? Yes but it may not be very useful.
