Hello,
I’m repairing my Breville espresso machine and upon examining the main board, it appears to have a blown MOV which I suspect is in the power supply circuit. I bought the machine used and it was dead as a door nail when I received it. As luck would have it, the side of the MOV with all the numbers is burned away. It appears to be in the AC input circuit. Machine is standard 110v. Maybe someone tried to plug it into 220v or something? Machine appears new and never used. I’m hoping whatever happened, the MOV blew as designed and protected the rest of the circuit. Marking on the PCB is znr1. I will attempt to upload a picture with the post. Any help identifying/sizing the MOV would be greatly appreciated. I’m a software engineer that has had some decent luck repairing obviously blown components on boards but I can’t claim to have much more than novice abilities when it comes to electronics.
It sounds like the MOV did it's job. Unfortunately a large current flowing can not be sensed as devices can take large currents without tripping the breaker (13A on UK 230V supply) - do you know if a breaker tripped? This suggest that other devices also saw the over voltage so are probably damaged too, assuming the MOV failed open circuit.
Have you tried removing the MOV and (carefully) seeing if it works?