Lincoln Electric SVM105-B SNUBBER RESISTOR TEST (cont.)

V300-PRO
TROUBLESHOOTING & REPAIR
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.
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.
F-30 F-30
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SNUBBER RESISTOR TEST (cont.)
L8604-1
L8604-1
SWITCH
SWITCH
9RW12WR 401/
403 1/ 84/ 5402/ 404
FIGURE F.9 - SNUBBER RESISTOR TEST POINTS
Check Test Result Conclusion Next Test Step Repair Action
Lead 401 to 25 ohms OK Continue
Terminal 12 >30 ohms R4 open Replace R4
<20 ohms R4 faulty
Lead 402 to 25 ohms OK Continue
Terminal 9 >30 ohms R5 open Replace R5
<20 ohms R5 faulty
Lead 403 to 25 ohms OK Continue
Terminal 12 >30 ohms R6 open Replace R6
<20 ohms R6 faulty
Lead 404 to 25 ohms OK Continue
Terminal 9 >30 ohms R7 open Replace R7
<20 ohms R7 faulty
TABLE F.4 SNUBBER RESISTORS TEST