hi first of all u should mention where the zener u have replaced?incold side or the hot side?by ur description ,i can assume that there is somewhere a s/c.i do not know this model n make , i have never come to know this set but one or another the basic principles r the same.the cliking as u say is it the relay that is chattering ,if it is so then the psu have a big problem.u should check the switching transistor,the parts around,the line o/p transistor n even the line transformer.best of luck