Kremins

Recently I was given a Sundance 724 Spa and upon wiring it up and turning on the breaker I found the controls not functioning. The display reads the temperature but you can not set the time or turning any of the jets/blower on or off or change any of the other controls. Its just like the buttons dont work. I ordered a new balboa replacement topside control for it thinking there was something wrong with that part but the new unit does the exact same thing. With both topside controls the pump will come on for a little while then shutoff kind of like the system is resetting it self. It seems to happen more often when I press the buttons on the topside control. Do I need to order a new circuit board or is there something else I should be looking at for this problem? Any help is appreciated. Thanks, Kremins