Samsung washing machine pcb Reparing ||

Samsung washing machine pcb repairing.one of them button is not working(water leavel).we checked the button after cutting its back cover .and then we found that the button is not a problem.it giving proper buzzer when checking with buzzer mode in multimeter .after that we trace the track than we found a bunch of zenar diodes.one of them are rusted.after replacing zenar diodes(IN4148)than pcb became in normal condition.