How can I fix my Fisher and Paykel 755T Ovens Controller?

Have a Under bench Fisher and Paykel Model 755T Oven that it's display has just stopped operating. It shows just a dot. Pressing the Ovens On/Off button generally gives a Relay clicking sound. Sometimes the display arcs up with the 180 degree default temperature and the oven will heat up and regulates to that temperature. Pressing any other button when the Controller has arced up causes the Display to disappear and the oven to shut down. Have cleaned the contacts I could find and Unit will now allow the Clock to be set, but this is lost as soon as touch the Oven On/Off Switch. I gather the Controller is Part Number 1548203 and is No Longer Available. Relay clicking implies that the power supply is not holding up. Any help would be appreciated.