Upon arrival found study area system not coming on. Checked inside unit and found no incoming power, checked light switch and it was on. Checked breaker and it was on. Checked power coming Into switch and I had power. Put switch back together and disconnected furnaces incoming power and checked for power. System had power. Reconnected incoming power and checked power at board, power was present, disconnected high voltage on trans form and power was present. Reconnected transformer and turned system on. System came on no issues. Cycle system 3 time and unit came on every time. System is working properly at this time but told homeowner to keep an eye on it because the control board may be going bad causing power to enter board but not sending it out to transformer. Gave quote to replace board just in case.