Lincoln Electric SVM123-A service manual SCR Output Bridge Replacement

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F-49	TROUBLESHOOTING & REPAIR	F-49

SCR OUTPUT BRIDGE REPLACEMENT

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the 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 tests/repairs safely, contact the Lincoln Electric Service Department for technical trou- bleshooting assistance before you proceed.

Call (216) 383-2531 or (800) 833-9353 (WELD).

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MATERIALS NEEDED

9/16” socket wrench 9/16” open end wrench

1/2” long-handled flat rachet wrench 1/2” socket wrench

1/2” open end wrench 3/8” socket wrench 5/16” socket wrench

Lincoln E1868 (Dow Corning #340) heat sink compound

IDEALARC DC-1000

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Contents Idealarc Electric and Magnetic Fields SafetyElectric Shock can kill Welding Sparks can cause fire or explosion Sûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Installation Output Technical Specifications Idealarc DCSelect Proper Location Electric Shock can KillElectrical Input Connections StackingFuse and Wire Sizes Reconnect ProcedureInput Power Supply Connections Ground ConnectionFigure A.3a Input Connection Diagram Figure A.3c -Input Connection Diagram Figure A.3d Input Supply Connection Diagram Output Connections Cutting Operation Connection for AIR/CARBON ARCIdealarc DC-1000 Operation Electric Shock can kill Safety InstructionsDesign Features Advantages Operational Features and ControlsGeneral Description Recommended Processes and EquipmentWelding Capability Return to Section Controls and SettingsNA-3 Automatic Wire Feeder Welding Procedure RecommendationsRemote Control of Machine Operation ARC Striking with Idealarc DC-1000 and the NA-3 Start Board Remote LN-8 SEMI-AUTOMATIC Wire FeederTable of Contents AccessoriesConnecting the NA-3 or LT-7 to OPTIONS/ACCESSORIESIdealarc DC-1000 Remote Output Control OptionalFigure C.2 NA-5 Wire Feeder Connection to Idealarc DC-1000 Connecting the NA-5 to the Idealarc DC-1000Connecting the LN-8 to the Idealarc DC-1000 Connecting the LN-9 Wire Feeder to the Idealarc DC-1000 Connecting the LN-7 Wire Feeder to the Idealarc DC-1000 Maintenance Routine and Periodic Maintenance Safety Precautions Electric Shock Can KillFigure D.1 Major Component Locations Idealarc DC-1000 Theory of Operation TOR, and Main Transformer Input Line VOLTAGE, ContacCONTROL, and Feedback Output RectificationCircuits Contactor HOLD-IN Protection DevicesFigure E.5 SCR Operation SCR OperationIdealarc DC-1000 Troubleshooting & Repair Locate Problem Symptom HOW to USE Troubleshooting GuideBoard can be damaged by static electricity PC Board Troubleshooting ProceduresControl Transformer Test Return Return to Master TOC Return Return to Section TOC Perform SCR Output Bridge Troubleshooting & Repair Function Problems Perform Firing Board Test Perform Control Board Test SCR Output Troubleshooting & Repair Control Transformer T2 Voltage Test Test DescriptionFigure F.1 Control Transformer Lead Location Test ProcedureFigure F.2 Control Transformer X1 and X2 Test Points Main Transformer T1 Voltage Test Test Description Figure F.4 Main Secondary Lead Test Points From Expected VAC Firing Board Test Test Procedure for Normal Firing Board Operation Figure F.7 Terminal Strip Jumper Wire Connections Figure F.8 Output Pilot Relay 4CR Location Then Table F.1 LED 7, 8 and 9 Check ListControl Board Test Figure F.9 Control Board LED and Pin Locations Test Procedure for Normal Control Board OperationIf LED 1 does not light, when the start switch is on Possible Problems Pertaining to the Control BoardFigure F.11 LED 2 Open Circuit Voltage Test Points If LED 4 lights Static SCR Test Figure F.12 Test ProcedureFigure F.13 SCR Heat Sink Assembly Test Points Static SCR Test Active SCR Test Active SCR Test Figure F.16 Heat Sink Assembly Test Points Battery Test Scope Settings Troubleshooting & Repair Troubleshooting & Repair Troubleshooting & Repair Troubleshooting & Repair Troubleshooting & Repair Troubleshooting & Repair Input Contactor 1CR Cleaning AND/OR Replacement Figure F.18 Input Contactor Cover Removal Cleaning ProcedureRemoval Contactor ReplacementInstallation SCR Output Bridge Replacement Figure F.22 Preparation For SCR Output Bridge Removal SCR Output Bridge RemovalFigure F.23 SCR Output Bridge Removal Removal of Individual SCR Heat Sink Assemblies SCR Output Bridge Installation SCR Heat Sink InstallationTOC Removal and Reassembly of Lift Bail Figure F.25 Lift Bail Removal Removal of Lift BailReassembly of Lift Bail Main Transformer Removal and Installation Figure F.26 Main Transformer Disassembly Main Transformer Disassembly and AssemblyCoil Removal Replacement Main Transformer DisassemblyTransformer Reassembly Transformer InstallationIdealarc DC-1000 Open Circuit Voltages Input Idle Amps and WattsIdealarc DC-1000 Electrical Diagrams Idealarc DC-1000 Wiring Diagram Codes 9919 Operating Schematic Control PC Board G1585 Layout Firing PC Board G1486-5 and above Layout Control PC Board G1585 Schematic Firing PC Board G1486-5 and above Schematic Output Snubber M14312 Schematic