Power-device testing

Welder IGBT Module Testing

Use the cropped terminal layout and meter sequence below. The important evidence is G/E/C identification, gate charge/discharge behavior and C-E short/open status, not a full-page scan.

IGBT terminal layout cropped from the service diagram and relabeled in English.

Meter-test sequence cropped from the source table and converted into an English decision guide.

English test sequence

Step	Action	Meaning
1	Identify G1/E1/C1 and G2/E2/C2.	Wrong terminals invalidate all readings.
2	Charge G-E using the high resistance range.	The gate should respond like a capacitive control terminal.
3	Measure C-E after charging.	Temporary conduction can appear after gate charge.
4	Short G-E to discharge, then re-test C-E.	A permanent C-E short is a failed module.
5	Repeat on the second transistor section.	Both sections should behave consistently.

After any failed IGBT, test the driver branches before power-up.

Do not stop at the IGBT

If the module failed, check the driver board, gate resistors, clamp parts, snubber network, rectifier bridge, output diode module and load path before applying mains power again.