I got a used ultrasonic cleaner with liquid damage for almost nothing and I am trying to repair it. So far I’ve confirmed that the board has a short circuit between live and neutral somewhere after the relay. Also, while reverse engineering it, I noticed something that seems weird. When the relay closes, it adds C3 in parallel to C2, both feeding the logic circuitry.
Well I would start of by testing the shit stained components on back bottom right. That looks to be the most significant amount of damage.
Or you can do it the good old read the smoke signals. And force power in to by putting a bigger fuse and letting the part that’s fucked burn up and show you the way. But you kina only have one chance at it.
What is the load on the relay?