System not responding to anything at time of arrival. Looked up manual and began trouble shooting process. Replaced batteries with new, reset controller, and put the unit in failure recall mode. Attempted to follow along with instructions with no success. Called Rob and spoke with him about it. He recommended visually checking the board and the compressor windings. Took outdoor unit apart after pulling disconnect and did so, with no apparent burns and with compressor windings all matching up. Restored power and unit began working. Asked customer to keep an eye on it and call us back if the unit fails to heat or cool again. Unit is running fine.