Jigsaw24.com's tech support team explain how to perform an SMC reset on your desktop Mac. This simple fix is worth a try if you're having problems with your iMac's fans, lights, general system performance or power management and the usual trick of turning it off and on again hasn't worked. If following the steps in the video doesn't help, UK viewers can call us on their local rate using the number on screen, or email [email protected].