The most common cause of a dead cruise control is a broken clock spring, but that eventually affects the horn and air bag too. That's a wound-up ribbon cable in a plastic housing under the steering wheel.
From your description I would start by looking for leaks in the vacuum hose going to the servo, then check the other vacuum hoses for leaks. A vacuum leak typically causes an inability to maintain speed but there is some indication the system is trying to work. After that, for a totally dead system, you need a scanner to see if the switches are being recognized when they're pressed, and if the solenoids in the servo are being activated. You'd also have to check for a broken throttle cable from the servo.
Wednesday, April 15th, 2015 AT 11:08 AM