Ultrasonic Cleaner Driver Circuit burned up

Thread Starter


Joined May 27, 2020
I have a 15L eBay ultrasonic cleaner. A few months ago the 5A fuse (F1) blew, I replaced it and the cleaner worked again........for a while.
The next time it failed, the breaker tripped on the garage, resistor R3 was burned, and all the transistors we shorted.
I replaced R1 and the transistors, as soon as I closed the Ultrasonic relay, F1 blew.
Being an electronics novice I'm having trouble working out what's going on and was hoping somebody here could help.
I've attached a photo of the main driver board, and a slide with the PCB tracks highlighted on the component side and components shown.
Please let me know what extra information you may need?