Responded to no ac call for main floor system, found outdoor unit not running when calling for ac. Found pitted contactor and defective capacitor. Made all repairs necessary to restore the unit to full health and eliminate all other concern, replaced capacitor, and contactor. Added hard start and topped system off with less than a pound or refrigerant. Checked both systems filters and pressures. Found second floor system short on return, and biological growth at indoor coil. Also noticed biological growth at main floor system as well.