Control Board Test Procedure - Lincoln Electric Classic 300 MP Service Manual

LINCOLN ELECTRIC

CONTROL BOARD TEST PROCEDURE

Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized
repairs performed on this equipment may result in danger to the technician or machine operator and will
invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety
notes and precautions detailed throughout this manual. If for any reason you do not understand the test
procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department
for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.
TEST DESCRIPTION
This test will determine if the Control Board is functioning normally.
MATERIALS NEEDED
9/16" Open-End Wrench
9/16" Nutdriver
3/8" Nutdriver
Volt/ohmmeter
Wiring Diagram
TEST PROCEDURE
1. Turn off the engine on the Classic 300 MP machine.
2. Perform the Case Cover Removal Procedure.
3. Using a 9/16" open-end wrench and a 9/16" nutdriver, remove the nut, bolt, lock washer and three
flat washers securing each side of the CV box to the fuel tank rail (two sets). See Figure F.7.
4. Carefully maneuver the CV box to allow access to the control board.
5. Using a 3/8" nutdriver, remove the two screws securing the finger guard panel to the machine. See
Figure F.7.
6. Locate the control board on the right lower side of the machine behind the CV box. See Figure F.7.
See Wiring Diagram.
7. Start the engine and observe the diagnostic LED in the wiring harness. Check for codes per Table
F.2. See Wiring Diagram.
8. Turn off the engine on the Classic 300 MP machine.
9. Using a volt/ohmmeter, perform the tests outlined in Table F.3. See Figures F.8 and F.9. See Wiring
Diagram.
10. If any of the tests fail the control board may be faulty.
11. If faulty, perform the Control Board Removal And Replacement Procedure.
12. Using a 3/8" nutdriver, attach the two screws securing the finger guard panel to the machine.
13. Using a 9/16" open-end wrench and a 9/16" nutdriver, attach the nut, bolt, lock washer and three
flat washers securing each side of the CV box to the fuel tank rail (two sets).
14. Perform the Case Cover Replacement Procedure.
Classic® 300 MP Service Manual
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