Circuit reference
Small Inverter Welder Board Stack Map
A general board-layer map for compact ZX7-style inverter MMA welders.
Quick Answer
Small inverter welders can often be diagnosed by board layer first: input/DC bus board, switching/driver board, output/feedback board and control/panel layer.
Board layers
Input/bottom board: bridge, capacitors, start resistor, relay, auxiliary supply. Switching/top board: MOSFETs, driver transformer and control module. Output/middle board: main transformer, output diodes, reactor, shunt, thermal switch and feedback.
Use case
Use this when a physical board is visible but the function is unclear. Use model-specific pages when exact connector names or voltage rails are available.