Lincoln Electric INVERTEC V275-S Service Manual page 48

F 18
MAIN SWITCH BOARD TEST (CONTINUED)
TEST PROCEDURE
1. Remove input power to the V275-S
machine.
2. Using a 5/16" nut driver, remove the case
wraparound cover.
3. Perform the Input Filter Capacitor
Discharge Procedure detailed earlier in
this section.
4. Locate the Main switch board.
Figure F.1
TROUBLESHOOTING & REPAIR
Figure F.3 - Main Switch Board Lead location
207A
204
J10
208
209
206
See
V275 S
202A
201
205
203A
Main IGBT Resistance Test
5. Use a analog volt/ohmmeter check for
shorted IGBT's. See Figure F.3.
6. The resistance from leads 205 to 206
should be very high. Less than 30 ohms
is a shorted IGBT. See Figure F.3.
7. The resistance from leads 203A to 208
should be very high. Less than 30 ohms
is a shorted IGBT. See Figure F.3.
8. The resistance from leads 202A to 204
should be very high. Less than 30 ohms
is a shorted IGBT. See Figure F.3.
9. The resistance from leads 207A to 201
should be very high. Less than 30 ohms
is a shorted IGBT. See Figure F.3.
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