Mean Well TN-3000 repair
An inverter with a pure sine wave output. This unit operates on 24V batteries.
The unit arrived faulty: all the LEDs were lit, and the fans were spinning. After a while, it completely stopped responding to the power button.
Diagnostics revealed a low-side fault: almost all the switches in the 24V circuit had burned out, as well as the fuses and transistor drivers.
After replacing all the faulty components and checking the power transformers for interturn short circuits, 24V was supplied from a laboratory source. The inverter started successfully.