Lincoln Electric SVM157-A service manual PC Board Troubleshooting Procedures

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F-3

TROUBLESHOOTING AND REPAIR

F-3

 

 

 

PC BOARD TROUBLESHOOTING PROCEDURES

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WARNING

ELECTRIC SHOCK can kill.

•Have an electrician install and service this equipment. Turn the input power OFF at the

fuse box before working on equipment. Do not touch electrically hot parts.

CAUTION

Sometimes machine failures appear to be due to PC board failures. These problems can sometimes be traced to poor electrical con- nections. To avoid problems when trou- bleshooting and replacing PC boards, please use the following procedure:

1.Determine to the best of your technical ability that the PC board is the most likely component causing the failure symptom.

2.Check for loose connections at the PC board to assure that the PC board is properly connected.

3.If the problem persists, replace the suspect PC board using standard practices to avoid static electrical damage and electrical shock. Read the warning inside the static resistant bag and perform the following procedures:

 

PC

board can be

 

damaged

by

static

 

electricity.

 

 

 

- Remove

your

body’s

ATTENTION

static

charge

before

opening

the

static-

Static-Sensitive

shielding bag. Wear an

Devices

anti-static wrist strap. For

Handle only at

safety, use a 1 Meg ohm

Static-Safe

resistive cord connected

Workstations

to a grounded part of the

 

equipment frame.

 

-If you don’t have a wrist strap, touch an un-

painted, grounded, part of the equipment frame. Keep touching the frame to prevent static build-up. Be sure not to touch any electrically live parts at the same time.

-Tools which come in contact with the PC board must be either conductive, anti-static or static-dissipative.

-Remove the PC board from the static-shield- ing bag and place it directly into the equip- ment. Don’t set the PC board on or near paper, plastic or cloth which could have a static charge. If the PC board can’t be installed immediately, put it back in the static-shielding bag.

-If the PC board uses protective shorting jumpers, don’t remove them until installation is complete.

-If you return a PC board to The Lincoln Electric Company for credit, it must be in the static-shielding bag. This will prevent further damage and allow proper failure analysis.

4.Test the machine to determine if the failure symptom has been corrected by the replacement PC board.

NOTE: It is desirable to have a spare (known good) PC board available for PC board troubleshooting.

NOTE: Allow the machine to heat up so that all electrical components can reach their operating temperature.

5.Remove the replacement PC board and substitute it with the original PC board to recreate the original problem.

a.If the original problem does not reappear by substituting the original board, then the PC board was not the problem. Continue to look for bad connections in the control wiring harness, junction blocks, and terminal strips.

b.If the original problem is recreated by the substitution of the original board, then the PC board was the problem. Reinstall the replacement PC board and test the machine.

6.Always indicate that this procedure was followed when warranty reports are to be submitted.

NOTE: Following this procedure and writing on the warranty report, “INSTALLED AND SWITCHED PC BOARDS TO VERIFY PROB- LEM,” will help avoid denial of legitimate PC board warranty claims.

POWER MIG 200

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Contents Safety Depends on You Power MIGCalifornia Proposition 65 Warnings SafetyARC Rays can burn Electric Shock can killIii Cylinder may explode if damagedSûreté Pour Soudage a L’Arc Précautions DE SûretéMaster Table of Contents for ALL Sections Installation Section Table of ContentsTechnical Specifications Power MIG Installation3INSTALLATIONA-3 Figure A.1 Dual Voltage Machine Input Connections Figure A.2 Triple Voltage Machine Input Connections Output Polarity ConnectionsShielding GAS GUN and Cable InstallationCylinder may explode if damaged Operation Section B Operation SectionWear eye, ear and body protec- tion OperationWire Size Conversion Parts Wire Drive RollProduct Description Recommended Processes and EquipmentWire Reel Loading READI-REELS, Spools or Coils Procedure for Changing Drive and Idle Roll SetsTo Start the Welder Idle Roll Pressure Setting Feeding Wire Electrode Making a WeldWire Feed Overload Protection Avoiding Wire Feeding ProblemsFAN Control Input Line Voltage VariationsAccessories Section Drive Roll Kits AccessoriesK363P READI-REEL Adapter Dual Cylinder Mounting KIT K1702-1Adapter KIT and Spool GUN InstalledPower MIG Maintenance Section Maintenance Liner Removal and REPLACE- Ment Cause poor wire feedingThis screw should only be gently tightened Overtightening will split or collapse the linerEnglish Metric Description Size GUN Handle DisassemblyMaintenance Power MIG Theory of Operation Section Line SwitchTheory of Operation Motor Control Board Output Rectification Contactor and Control BoardFigure E.4 Optional Circuits Control BOARD, GUN Trigger and Wire Drive MotorThermal and Overload Protection Wirefeed Overload ProtectionPower MIG Troubleshooting and Repair Section F Troubleshooting and Repair SectionHow To Use Troubleshooting Guide Troubleshooting and RepairPC Board Troubleshooting Procedures Perform the Main Transformer Perform the Output Contactor Avoid contact with any portion These capacitors is toxicYour body Function Problems Tachometer Feedback Test Welding Problems Weld bead is narrow or ropy Make sure the welding proce Test Description Main Transformer TestMaterials Needed Main Transformer Test ON/OFF Power Switch will be hot during these testsX10 Input Voltage Test Points Table F.1. Test PointsWire Drive Motor and Tachometer Feedback Test Figure F.4. Plug J4 Test ProcedureTest for Supply Voltage to Tachometer Disconnect the main AC input power to the machineVDC Test for Feedback Voltage to Control BoardOutput Bridge Rectifier Test Output Bridge Rectifier Test Test ProcedureContactor Test Figure F.7. Contactor Terminals and Leads Contactor TestTypical Output Voltage Waveform Machine Loaded MAX TAP G Volts 10.0Normal Open Circuit Voltage Waveform MAX TAP G Volts 20.0Machine Loaded to 180 Amps AT 16 VDC Scope Settings Volts 20.0 Description Control Board ReplacementProcedure Control Board ReplacementWire Drive Motor Assembly Replacement Wire Drive Wire Drive Motor Assembly ReplacementBolt Gas Hose TOC Output Diode Bridge Rectifier Replacement Output Diode Bridge Rectifier Mounting Bracket Mounting Bolts Rectifier Power MIG Output Capacitors Replacement Figure F.14. Capacitor Bank Location Output Capacitors ReplacementLead Mounting Bolts Nuts & Lock washers Places Power MIG Main Transformer Replacement 41TROUBLESHOOTING and REPAIRF-41See Figure F.17 Main Transformer ReplacementFigure F.17. Leads X9, X10, 104B,104C, & H1B ReplacementX2 X3 X4 X5 X6 X7 Lead Power MIG FAN BLADE/MOTOR Replacement Perform the Output Capacitor Bank Removal Procedure FAN BLADE/MOTOR ReplacementOutput Contactor Replacement Figure F.24 Output Contactor ReplacementMounting Bolts Retest After Repair Table of Contents Electrical Diagrams Section Electrical DiagramsWiring Diagram Power MIG 200 208/230VSchematic Control PC Board G3851-1 PC Board ASSEMBLY-CONTROLSVM Error Reporting Form
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