Lincoln Electric SVM104-A service manual Troubleshooting & Repair

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Section TOC

Master TOC

TROUBLESHOOTING & REPAIR

F-30

POWER BOARD TEST

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Test D: Test for 0.2 VDC to 0.3 VDC Gate Drive Voltages to the SCR Module.

NOTE: This test requires that the torch trigger be pulled to activate the circuit. Be sure to use an isolated meter because of the high voltage and high frequency produced.

NOTE: This test requires testing DC voltages. Polarity must be observed.

1.Locate and insert probes into the following Power Board plug locations (See Figure F.11):

a.Insert the NEGATIVE probe into Plug 1J21 (lead #383 -) lead cavity.

b.Insert the POSITIVE probe into Plug 3J20 (lead G2 +) lead cavity.

2.Turn the ON/OFF Power Switch to ON.

3.Pull torch trigger. When air pre- flow times out and the pilot arc is established, 0.2 VDC to 0.3 VDC should be present.

4.Release torch trigger.

5.Locate and insert probes into the following Power Board plug locations (See Figure F.11):

a.Insert the NEGATIVE probe into Plug 1J21 (lead #383 -) lead cavity.

b. Insert the POSITIVE probe into Plug 4J20 (lead G1 +) lead cavity.

2.Turn the ON/OFF Power Switch to ON.

3.Pull torch trigger. When air pre- flow times out and the pilot arc is established, 0.2 VDC to 0.3 VDC should be present.

4.Release torch trigger. Turn ON/OFF Power Switch to OFF.

a.If specific voltages ARE NOT present, check Power Board Plugs J20 and J21 and Control Board Plug J6 for loose or faulty wiring.

b.If no loose or faulty wiring is found, the Power Board, Control Board, or SCR module could be faulty. Replace.

PRO-CUT 60

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Contents SVM104-A Electric Shock can kill SafetyWelding or Cutting Sparks can cause fire or explosion Electric and Magnetic Fields IiiSûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Table of Contents Technical Specifications PRO-CUT InstallationTilting Safety Precautions Electric Shock can KillSelect Proper Location High Frequency Interference ProtectionInput Electrical Connections ➁ ➂ ➀ ➃Ground Connection Fuse and Wire SizesInput Power Supply Connections AIR Input Connections 208/230/460 VAC machines Reconnect ProcedureWork Output ConnectionsOperation Section Table of ContentsElectric Shock can kill OperationRecommended Processes and Equipment Operational Features and ControlsDesign Features Advantages General DescriptionLimitations Controls and SettingsCutting and Gouging Capability ON/OFF Operating StepsUse Pilot Arc Properly Cutting Procedure RecommendationsCutting Thin Gauge Sheet Metal Cutting Expanded Metal Figure B.3 -- Gouging Metal Return to Section TOC Accessories Section OPTIONS/ACCESSORIES AccessoriesSection D Maintenance SectionProcedure Description MaintenanceSafety Precautions Capacitor Discharge ProcedureFigure D.1 Capacitor Discharge Procedure ProcedurePerform the following daily Routine and Periodic MaintenanceMaintenance PRO-CUT Theory of Operation Section Theory of Operation SectionInput Line Voltage and Main Transformer Theory of OperationFigure E.3 Output Rectification, Control and Feedback Output Rectification Control and FeedbackHigh Voltage / High Pilot ARC Theory of OperationFigure E.7 Transistor Switching Operation Transistor Switching OperationThermal Sensor Pulse Width ModulationThermal Protection ThermostatPRO-CUT Troubleshooting & Repair Section HOW to USE Troubleshooting Guide Troubleshooting & RepairBoard can be dam- aged by static electricity Troubleshooting PC Board Troubleshooting ProceduresTroubleshooting Guide PRO-CUT Troubleshooting GuideConnect ALL Input Disconnect ALL Input Machine Troubleshooting & Repair Function Problems AIR Flow Problems Cutting Problems Power Board Connector Location Control Board Connector LocationCapacitor Discharge Procedure Insulated Pliers Gloves Figure F.19-Capacitor Discharge ProcedureTest Description Work Torch and Cable Resistance Test ProcedureFigure F.4 Torch and Cable Resistance Test Points Internal Trigger Safety Circuit TestReturn to Return to Section TOC Figure F.6-Control Board and 4-pin Locations Test Description Transistor Module TestTest Procedure J21 Main Transformer Test Test a Main Secondary Voltage Test Test ProcedureCR2 Power Board Test Figure F.11-Power Board Test Points Transistor Module Test Troubleshooting & Repair High Voltage Transformer and Circuit Test Figure F.12-High Voltage Test Component Locations Test C Test Resistance of High Voltage Transformer Secondary REMOVAL/REPLACEMENT Description ON/OFF Power Switch Removal➂ ➃ ➄ REMOVAL/REPLACEMENT ProcedureControl Board Removal To Section TOC Power Board Removal Figure F.14-Power Board Removal/Replacement Return to Return to Section TOC Transistor Module Removal 41TROUBLESHOOTING & RepairRemoval Procedure SCR Module Removal Socket Head CAP Screws Torque to Power Board REMOVAL/ Replacement Procedure FAN Blade and FAN Motor REMOVAL/REPLACEMENT Figure F.17-Fan Blade & Fan Motor To Section TOC Torch Head REMOVAL/REPLACEMENT Figure F.18-Torch Head Removal/Replacement Section TOC Recommended Meters for Machine Output Tests Maximum Acceptable Output Voltage AT Minimum Output SettingRetest After Repair Input Idle AmpsPRO-CUT Electrical Diagrams Electrical DiagramsStatus Board Schematic Diagram H E M a T I C Bypass Board Schematic Diagram M15603Bypass Board Schematic Diagram M17322 PRO-CUT Electrical Diagrams Identification Control BoardPower Board Identification Power BoardM15601 Status Status PC BoardM15601 Status PC BoardBypass Bypass PC Board M15603Bypass PC Board M15603 Bypass PC Board M17322 Bypass PC Board M17322 0 , J 2 Wiring Diagram for Codes 10112Wiring Diagram for Codes 9819 Control Board Schematic Drawing G2015 Power Board Schematic Design SVM Error Reporting Form