Lincoln Electric INVERTEC V300-PRO SVM105-B Service Manual page 60

F-30
W R
1. Turn main Power off.
2. Perform Input Filter Capacitor Discharge proce-
dure.
3. Remove leads 401,402 403 & 404 from theSwitch
Boards.
4. Test for 25 ohms resistance from lead 401 to termi-
nal 12 on Switch Board.
Check Test Result
Lead 401 to 25 ohms
Terminal 12 >30 ohms
<20 ohms
Lead 402 to 25 ohms
Terminal 9 >30 ohms
<20 ohms
Lead 403 to 25 ohms
Terminal 12 >30 ohms
<20 ohms
Lead 404 to 25 ohms
Terminal 9 >30 ohms
<20 ohms
TROUBLESHOOTING & REPAIR
SNUBBER RESISTOR TEST (cont.)
FIGURE F.9 - SNUBBER RESISTOR TEST POINTS
401/ 1/ 9
403 8
L8604-1 L8604-1
TABLE F.4 SNUBBER RESISTORS TEST
Conclusion
OK
R4 open
R4 faulty
OK
R5 open
R5 faulty
OK
R6 open
R6 faulty
OK
R7 open
R7 faulty
V300-PRO
12 4/ 402/ R W
5 404
SWITCH SWITCH
a. If 25 ohms is measured, Resistor R4 is OK.
b. If 30 ohms or more is measured, Resistor R4 is
faulty and must be replaced.
c. If 20 ohms or less is measured, Resistor R4 is
faulty and must be replaced.
5. Repeat same procedures to test R5, R6, and R7 per
Table F.4.
Next Test Step Repair Action
Continue
Replace R4
Continue
Replace R5
Continue
Replace R6
Continue
Replace R7
F-30