Lincoln Electric SVM112-B service manual Trigger Circuit and Wiring Harness Test

Models: SVM112-B

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F-120

F-120

TROUBLESHOOTING & REPAIR

TRIGGER CIRCUIT AND WIRING HARNESS TEST (continued)

FIGURE F.43 - PROTECTION BOARD PLUG/HEADER LOCATIONS

PROTECTION BD

 

 

 

1

1

4

7

1

1

1 2 1

 

1

1

1

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

4

 

16

14

 

6

6 11

14

 

6

 

 

4

 

J32

J35

4

4

J39

 

J30

J31

J33

 

J34

 

J36 J37 J38

 

 

 

 

 

 

 

 

 

 

 

3

 

 

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TEST PROCEDURE

1.Remove main input supply power to the machine.

2.With the 3/8" nut driver, remove the 4 screws that hold the handle to the machine.

3.Remove the rubber gasket (cover seal) from the lift bail.

4.With the 5/16" nut driver, remove the sheet metal screws from the case top.

5.With the 5/16" nut driver, remove the screws holding the right and left case sides. Remove the case sides by lifting up and out.

6.Perform the Capacitor Discharge Procedure described earlier in this section of the manual.

WARNING

Before continuing with the test procedure, perform the capacitor discharge proce- dure to avoid electric shock.

7.After you have completed the capacitor dis- charge procedure for all four switch boards, remove the PC board cover. Use the 5/16" nut driver.

8.Remove plugs J34, J37, and J38 from the protection board. See Figure F.1 for loca- tion. Continue with the following checks:

NOTE: Do not remove plug J33 from the pro- tection board.

A.With the volt/ohmmeter, check for continu- ity between J37 - pin 1 and J37 - pin 4 of header J37. There should be no continuity.

B.Connect a jumper between J34 - pin 11 and J34 - pin 14 of header J34 of the pro- tection board. This simulates the closing of the trigger on wire feeder 1 or the remote.

C.With the volt/ohmmeter, check for continu- ity again between J37 - pin 1 and J37 - pin 4 of header J37. There should be continu- ity now. Remove the jumper.

D.With the volt/ohmmeter, check for continu- ity between J37 - pin 2 and J37 - pin 3 of header J37. There should be no continuity.

E.Connect a jumper between J34 - pin 4 and J34 - pin 7 of header J34 on the protection board. This simulates the closing of the trigger on wire feeder 2.

F.With the volt/ohmmeter, check for continu- ity again between J37 - pin 2 and J37 - pin 3 of header J37. There should be continu- ity now. Remove the jumper and connect plugs J34, J37, and J38 back into the pro- tection board.

If the continuity tests above detect a fault, replace the protection board.

9.Remove plug J37 from the protection board and inspect its pins and leads. Make sure that the TRIG 1, TRIG 2, and COMMON pins of plug J37 are not short- ed together (pins 1, 2, 3, 4, respectively). Make sure that leads #371, #372, #373, and #374 are not exposed. See the Auxiliary Transformer #1 Secondary Circuit Wiring Diagram, Figure F.44.

10.Connect plug J37 to the Protection board. If you found no problem with plug J37 pins and leads, replace the display board.

11.After the tests are completed and the problem successfully repaired, reconnect all plugs to their respective boards. Replace the PC board cover with the two sheet metal screws.

12.Install the machine case sides and top.

13.Install the handle and the lift bail rubber gasket.

POWER WAVE 450

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Lincoln Electric SVM112-B Trigger Circuit and Wiring Harness Test, Figure F.43 Protection Board PLUG/HEADER Locations