I pulled all of the old Total Control and Irritrol clocks off my properties quite some time ago. Similar problems where the fuse blew and the clock went dead. Got sick and tired of carrying spare fuses too. Seem to remember some of these older models had a fuse block mounted in the rear of the controller face plate - to access you need to remove the small phillips screws and carefully open the back panel to avoid snapping the plastic dog ears. Presuming no field wiring problem or funky a/c power to the controller is the culprit, I'd replace it with an up-dated unit. Personally I haven't seen one of these controllers with a build date newer than '97 or so.