SEM Security Systems
a division of Southeast Mobility Inc
So, your yellow light is on, the keypad is beeping, you've pressed *2 and the keypad is displaying a 2, or it reads out AC Loss.

Your system is powered by a 16.5 volt 40 VA transformer. You will find it plugged into a wall outlet somewhere in the home and it may or may not be near the main panel. It will be white cube about 3 inches in size and there will be a screw holding it to the wall outlet. Once you find this transformer you should plug a fan or other appliance into the open side of the outlet. If the appliance works in this outlet, then you probably have a bad transformer and you should contact us to schedule a service call for replacement.

If the appliance does not work, then you have lost power to that outlet and you should check your breakers or contact a qualified electrician to trouble shoot the problem.