Checking The Semiconductor Module Of 15Ap1 - ESAB Caddy Tig 2200i AC/DC Service Manual

Checking the semiconductor module of 15AP1

Measuring points for the semiconductor module, PM1
Disconnect the machine from the mains and follow the instructions below.
Measurements 2 -- 6: Use a multimeter in diode test position to measure the diodes.
Measure with the positive and negative of the multimeter connected as shown in the picture
above. The main transformer must be connected to terminals T1 and T2.
1. Resistor R31 (and thyristor TY1 in parallel): measure the resistance of R31. It must be
12 ohm (on some boards the resistance of R31 is 6.8 or 10 ohm, which are also
approved values).
2. PM1, diode P1D: measure between resistor R31 and terminal N1.
PM1, diode P2D: measure between resistor R31 and terminal N2.
The forward voltage drop must be 0.4 to 0.6 V.
3. PM1, diode N1D: measure between the negative of capacitor 15C1 and terminal N1.
PM1, diode N2D: measure between the negative of capacitor 15C1 and terminal N2.
The forward voltage drop must be 0.4 to 0.6 V.
4. PM1, diode D2: measure between the negative of capacitor 15C1 and terminal T2.
The forward voltage drop must be 0.3 to 0.5 V.
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S0740 800 179/E071123/P64