Lincoln Electric INVERTEC V300-PRO SVM105-B Service Manual page 79

F-49
309 310
J7
501
504
6. Test for 18 VAC input from Auxiliary Transformer
between leads 504 and 501 (J7-pin 5 & pin 6) on
Power Board.
If 18 VAC is not correct, check the 3 amp fuse, the
Auxiliary Transformer and associated wires.
7. Test for 15 VDC output between leads 275D (-) and
302 (+) (J6-pin1 & pin 6) on Power Board.
If 15 VDC output is not present, replace Power
Board.
NOTE: If relays energized in Step 4a, skip to Step 10.
8. Test for 24 VAC from lead 211A to lead 212A (J6-
pin 4 & pin 9).
If 24VAC is not present, test the Auxiliary trans
former and associated wires. The Control Board or
thermostats may also be defective. (See Fig. F.24).
TROUBLESHOOTING & REPAIR
POWER BOARD TEST (cont.)
FIGURE F.23 - POWER BOARD TEST POINTS
L8033
V300-PRO
POWER BOARD
J14
313
311
9. Test for 24VDCfrom lead 309 (+) to lead 313 (-)
(J7pin 2 to J14 pin 2).
If 24VDC is not present but 24VAC (step 8) is cor
rect, the Power Board is defective.
10. Test for 24VDC from lead 309(+) to lead 310(-) (J7
pin 2 to J7 pin 4).
If 24 VDC is not present, check the voltage from
lead 311(+) to lead 313(-).
If the voltage is greater than 1VDC, perform the
Protection Board test.
If the voltage is approximately 1vdc and the 24vdc
is not present between leads 309 & 310, the
Power Board is defective
F-49
212A
301
302
J6
275D
211A
305