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==Overview==
The SMC has roles in controlling thermal and power management, battery charging, video mode switching, [[Sleep mode|sleep and wake]], [[Hibernation (computing)|hibernation]], and [[Light-emitting diode|LED]] indicators. It also enables enforcement of the [[Mac OS X]] [[End-user license agreement|End User License]], allowing it to identify when it is running on non-Apple hardware.<ref>{{cite web|title=Interview with Andy Hall, Product Manager for Oracle VM VirtualBox|url=http://twit.tv/floss130}}</ref>
Apple releases occasional model-specific updates to SMC firmware which correct bugs and defects in the system.<ref>[http://support.apple.com/kb/index?page=search&q=SMC+update Search of SMC update information in Apple's knowledge base]</ref>
Corrupted SMC firmware, whatever the cause, is not entirely uncommon{{vague|date=June 2015}} and may lead to operational problems. Resetting the SMC may resolve certain issues with:<ref>[http://support.apple.com/en-us/HT201295 Intel-based Macs: Resetting the System Management Controller (SMC)]</ref>
===Fans===
*Cooling fans running at high speed.
===Lights===
*Keyboard Backlight Issues.
*Incorrect behavior with the Status Indicator Lights or Battery Indicator Lights.
*Backlight displays not responding to ambient light changes.
===Power===
*Non-responsive power button
*Unexpected sleep or shutdown
*Battery not charging properly
*MagSafe [[Light-emitting diode|LED]] displays incorrect activity
===System Performance===
*Computer running slowly despite low [[Load (computing)|CPU load]]
*Long "Bounce" times for application icons in the dock.
===External displays and [[Photodetector|Ambient Light Sensing]]===
*Unexpectedly switching into or out of target display mode for external displays.
===Port Illumination===
*I/O Ports on some late model 2013 Mac Pro's don't illuminate when the computer is moved.
Resetting the SMC is usually accomplished by removing all power from the system for a period of time (by unplugging the [[Mains electricity|mains]] connector or removing the battery) or by operating the power button in a special way. Apple provides model-specific instructions for SMC reset.<ref>[http://support.apple.com/kb/HT3964 Intel-based Macs: Resetting the System Management Controller (SMC)]</ref>
==See also==
* [[Power management integrated circuit]] (PMIC)
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