: If the power indicator is on but no ultrasonic waves are visible, it usually points to a burned-out transducer or a generator fault .
: A red LED (HL1) protected by a diode (VD1) indicates the generator is operational. Operational Highlights Efficiency : The : If the power indicator is on but
: The ultrasonic generator should never be switched on without the piezo-emitter submerged in water , as running it "dry" can destroy the circuit. Retona USU-0707 " is a compact ultrasonic washing
Retona USU-0707 " is a compact ultrasonic washing device consisting of a power supply unit and a small piezoceramic radiator (activator). The device works by emitting ultrasonic waves into water to dislodge dirt from fabric fibers. Common successful replacements include the , , or
: Often an unmarked NPN transistor. Common successful replacements include the , , or .
Repair enthusiasts and technical forums describe the internal circuitry of the Retona USU-0707
model was designed with an increased power consumption (from 9W to 30W in some iterations) to improve the efficiency of the ultrasonic emission into the liquid.