Performed diagnostic on 7 year old Lennox system. Met with Chris’s wife, Chris’s parents are the homeowners. System stopped working a couple days ago. It is not turning on at all and not blowing any air throughout the house. Cycled Susie, for cooling. Found indoor and outdoor units completely unresponsive. Checked for power at indoor unit. Reset breaker. Transformer was receiving power but was extremely hot to the touch. System came on and started Cooling. Recommend replacing transformer. They stated that a couple days ago they tried to plug in a portable air conditioner into the outlet, and them the unit wasn’t working since then. Portable AC most likely caused a power surge to the unit and caused some damage to the transformer. Spoke to Chris over the phone and approved immediate repair. Needs to talk to his parents about everything else. Replaced transformer. System is operational upon departure.