I completed a callback service. On my arrival found the outdoor unit not coming on due to no 24 V call at the contactor. Traced the problem inside and found a loose connection near the control board low-voltage terminals, after I took the panel off and manipulated these wires the system came on, I went ahead and re-stripped and reconnected these wires making sure all of the screws were tight, when I restored power everything came on again. Moved wires around while system was running just to make sure I did not notice any more interruption. Everything seems to be working as it should on my departure.