Lincoln Electric SVM157-A service manual Output Bridge Rectifier Test, Test Procedure

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F-20

TROUBLESHOOTING AND REPAIR

F-20

OUTPUT BRIDGE RECTIFIER TEST (continued)

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TEST PROCEDURE

1.Remove input power to the POWER MIG 200 machine.

2.Using the 3/8” nutdriver, remove the left case side.

3.Locate and disconnect the negative lead from the output rectifier bridge assembly. Be sure there is no electrical contact between the rectifier and the lead. See Figure F.6.

NOTE: Do not disassemble the rectifier assembly.

4.Test for “shorted” or “leaky” diodes by checking from the anodes to the cathodes of the diode heatsink plates. The readings should be high resistance in one polarity and low resistance in the opposite polarity.

5.If any of the diodes are “leaky” or “shorted” the output rectifier assembly should be replaced.

6.When the test is complete, replace the negative output lead previously removed.

7.Replace the left case side.

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Figure F.6. Rectifier Test Points

+

-

Negative Lead

POWER MIG 200

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Contents Power MIG Safety Depends on YouSafety California Proposition 65 WarningsElectric Shock can kill ARC Rays can burnCylinder may explode if damaged IiiPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcMaster Table of Contents for ALL Sections Table of Contents Installation SectionInstallation Technical Specifications Power MIG3INSTALLATIONA-3 Figure A.1 Dual Voltage Machine Input Connections Output Polarity Connections Figure A.2 Triple Voltage Machine Input ConnectionsGUN and Cable Installation Shielding GASCylinder may explode if damaged Operation Section Operation Section BOperation Wear eye, ear and body protec- tionProduct Description Wire Drive RollWire Size Conversion Parts Recommended Processes and EquipmentProcedure for Changing Drive and Idle Roll Sets Wire Reel Loading READI-REELS, Spools or CoilsTo Start the Welder Feeding Wire Electrode Making a Weld Idle Roll Pressure SettingFAN Control Avoiding Wire Feeding ProblemsWire Feed Overload Protection Input Line Voltage VariationsAccessories Section K363P READI-REEL Adapter AccessoriesDrive Roll Kits Dual Cylinder Mounting KIT K1702-1Installed Adapter KIT and Spool GUNPower MIG Maintenance Section Maintenance This screw should only be gently tightened Cause poor wire feedingLiner Removal and REPLACE- Ment Overtightening will split or collapse the linerGUN Handle Disassembly English Metric Description SizeMaintenance Power MIG Line Switch Theory of Operation SectionTheory of Operation Output Rectification Contactor and Control Board Motor Control BoardControl BOARD, GUN Trigger and Wire Drive Motor Figure E.4 Optional CircuitsWirefeed Overload Protection Thermal and Overload ProtectionPower MIG Troubleshooting and Repair Section Troubleshooting and Repair Section FTroubleshooting and Repair How To Use Troubleshooting GuidePC Board Troubleshooting Procedures Perform the Main Transformer Perform the Output Contactor These capacitors is toxic Avoid contact with any portionYour body Function Problems Tachometer Feedback Test Welding Problems Weld bead is narrow or ropy Make sure the welding proce Main Transformer Test Test DescriptionMaterials Needed ON/OFF Power Switch will be hot during these tests Main Transformer TestX10 Table F.1. Test Points Input Voltage Test PointsWire Drive Motor and Tachometer Feedback Test Test Procedure Figure F.4. Plug J4 Disconnect the main AC input power to the machine Test for Supply Voltage to TachometerTest for Feedback Voltage to Control Board VDCOutput Bridge Rectifier Test Test Procedure Output Bridge Rectifier TestContactor Test Contactor Test Figure F.7. Contactor Terminals and LeadsVolts 10.0 Typical Output Voltage Waveform Machine Loaded MAX TAP GVolts 20.0 Normal Open Circuit Voltage Waveform MAX TAP GMachine Loaded to 180 Amps AT 16 VDC Scope Settings Volts 20.0 Control Board Replacement DescriptionControl Board Replacement ProcedureWire Drive Motor Assembly Replacement Wire Drive Motor Assembly Replacement Wire DriveBolt Gas Hose TOC Output Diode Bridge Rectifier Replacement Output Diode Bridge Rectifier Mounting Bracket Mounting Bolts Rectifier Power MIG Output Capacitors Replacement Output Capacitors Replacement Figure F.14. Capacitor Bank LocationLead Mounting Bolts Nuts & Lock washers Places Power MIG 41TROUBLESHOOTING and REPAIRF-41 Main Transformer ReplacementMain Transformer Replacement See Figure F.17Replacement Figure F.17. Leads X9, X10, 104B,104C, & H1BX2 X3 X4 X5 X6 X7 Lead Power MIG FAN BLADE/MOTOR Replacement FAN BLADE/MOTOR Replacement Perform the Output Capacitor Bank Removal ProcedureOutput Contactor Replacement Output Contactor Replacement Figure F.24Mounting Bolts Retest After Repair Electrical Diagrams Table of Contents Electrical Diagrams SectionPower MIG 200 208/230V Wiring DiagramSchematic Control PC Board PC Board ASSEMBLY-CONTROL G3851-1SVM Error Reporting Form