When an ultrasonic bonding machine fails to produce sound waves, first check for acoustic output by disassembling the mold. If sound waves are still absent, further inspect whether the current meter needle oscillates. If the needle oscillation appears normal, examine whether the transducer wires have become detached.

For the phenomenon of no ultrasonic wave output in the ultrasonic bonding machine, first determine whether there is ultrasonic current output. Observe whether the load meter shows oscillation; normal no-load current for ultrasonic waves is typically around 0.5A. If this current is absent, it generally indicates damage to the ultrasonic generator or ultrasonic circuit board. Focus on inspecting the maintenance circuit section.

An output exceeding 0.5A-1A indicates the ultrasonic generator is producing surge current, likely due to ineffective transmission to the ultrasonic sensor section—such as an open circuit in the intermediate connection wires. Alternatively, the ultrasonic sensor may be internally damaged. The simplest method to diagnose this is by swapping with a known-good sensor. If the current significantly exceeds 1A beyond normal no-load levels, focus inspection on the transducer assembly—check for cracks in aluminum components or the horn.

After confirming an issue with the ultrasonic generator, focus on verifying whether the ultrasonic trigger TEST in the circuit activates. Typically, this circuit is controlled by a relay. If the relay moves but no current is output, it indicates damage to the post-impact circuit. If even the drive relay fails to move, inspect the relay's drive circuit.

The most common issue in the post-oscillation circuit is damage to the power board. Power board failures account for 50% of all ultrasonic welder malfunctions. Replacing and maintaining ultrasonic power boards is straightforward and will not be repeated here. Other failures involve damaged components within the resonant circuit, such as the tuning inductor, resonant capacitor, power transistor bias components, and power transistor base drive components.

After ruling out the above issues, inspect the output circuit. This circuit connects to the ultrasonic transducer, forming a parallel resonant circuit with it. Any component failure or value deviation within this circuit must be completely eliminated.