Lincoln Electric INVERTEC SVM101-B Service Manual page 71

F-41
OVERVOLTAGE PROTECTION DC TRIGGER CIRCUIT TEST (cont.)
309 310
J7
501
504
8. Test for 15 VDC supply voltage between leads 302
and 275D on Power Board.
a. If 15 VDC is present, test is OK. Go to step 9.
b. If 15 VDC is not present, the Power Board may
be faulty. Check for 18 VAC input voltage at
lead 501 and 504 (J7).
If 18 VAC is present the Power Board is faulty
and must be replaced.
9. Test for 0-1 VDC (DC trigger circuit) between leads
305 and 275D on Power Board.
a. If 0-1 VDC is present, DC trigger circuit is oper-
ating properly.
b. If 15 VDC is present, go to step 10.
TROUBLESHOOTING & REPAIR
FIGURE F.18 - POWER BOARD TEST POINTS
L8033
V300-I
POWER BOARD
J14
313
311
10. Test for 0-1 VDC between leads 301 and 275D on
Power Board.
a. If 0-1 VDC is present, AC trigger, Control
Board, and Power Board are operating proper-
ly.
b. If 15 VDC is present, go to Thermal Protection
AC Trigger Circuit Test .
F-41
212A
301
302
J6
275D
211A
305