Lincoln Electric SVM149-A service manual PC Board Troubleshooting Procedures

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TROUBLESHOOTING & REPAIR

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PC BOARD TROUBLESHOOTING PROCEDURES

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WARNING

ELECTRIC SHOCK can kill.

Have an electrician install and service this equipment. Turn the machine OFF before working on equipment. Do not touch electrically hot parts.

Sometimes machine failures appear to be due to PC board failures. These problems can sometimes be traced to poor electrical connections. To avoid prob- lems when troubleshooting 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 caus- ing 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:

Remove the PC Board from the static-shielding bag and place it directly into the equipment. 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 symp- tom has been corrected by the replacement PC board.

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 termi-

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ATTENTION Static-Sensitive Devices Handle only at Static-Safe Workstations

Reusable

Container

Do Not Destroy

PC Board can be damaged by static electricity.

Remove your body’s static charge before opening the static- shielding bag. Wear an anti-sta- tic wrist strap. For safety, use a 1 Meg ohm resistive cord con- nected to a grounded part of the equipment frame.

If you don’t have a wrist strap, touch an unpainted, 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.

nal 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 PROBLEM,” will help avoid denial of legitimate PC board warranty claims.

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

PRO-CUT 25

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Contents PRO-CUT Safety Cylinder may explode if damaged Précautions DE Sûreté SafetyMaster Table of Contents for ALL Sections PRO-CUT Installation Section Table of ContentsTechnical Specifications PRO-CUT 25 K1756-1 InstallationSelect Proper Location Safety Precautions Electric Shock can KillHigh Frequency Interference Protection Input Electrical ConnectionsGAS Input Connections Torch Output ConnectionsPRO-CUT Table of Contents Operation Section Preheat Temperature for Plasma Cutting Safety PrecautionsOperation DescriptionDesign Features Advantages Operational Features and ControlsUser Responsibility Consumable Life Cutting CapabilityLimitations Controls and SettingsPilot ARC Discussion Apparently wrong, reset the machine by turningGeneral In All Cases Procedure RecommendationsPRO-CUT Accessories General Options Accessories Maintenance Electric Shock can kill Routine MaintenancePRO CUT PRO-CUT Table of Contents Theory of Operation Section General Description Theory of OperationInput Line VOLTAGE, and Auxiliary Transformer Figure E.3 Precharge and Protection Precharge and ProtectionReturn Return to Section TOC Main TransformerFigure E.5 Plasma Output Section and Torch Figure E.6 Control Board Control BoardProtection Circuits Safety PARTS-IN-PLACE ProtectionAccidental Operation Protection Insulated Gate Bipolar Transistor Igbt Operation Table of Contents Troubleshooting & Repair Section HOW to USE Troubleshooting Guide Troubleshooting & RepairPC Board Troubleshooting Procedures Output Problems Function Problems See the Operation section Troubleshooting & Repair LED Function Problems Description Input Filter Capacitor Discharge ProcedureRight Side of Machine Discharge ProcedureMain Inverter Board Resistance Test Right Side of Machine IGBT’s D2 D1 D11 D10 PRO-CUT Input Board Voltage Test Test Points Fan PRO-CUT Main Inverter Board Voltage Test P2 P1 P2 P1 PRO-CUT Torch Continuity and Solenoid Test Torch Continuity and Solenoid Test Torch Continuity and Solenoid Test PRO-CUT AIR/GAS Solenoid Test AIR/GAS Solenoid Test Control Board Removal and Replacement Small Red Cap Screws Over tighten Input Board Removal and Replacement Input Board Input Board Removal & Replacement PRO-CUT Main Inverter Board Removal and Replacement Main Board Main Inverter Board Removal & Replacement PRO-CUT Switch Removal and Replacement PRO FAN Removal and Replacement Fan Do Not Over tighten Machine Input and Output Retest After RepairTable of Contents Electrical Diagrams Section Electrical DiagramsInput Voltage Board Pressure SCHEMATIC- Control Printed Circuit Board Sheet Electrical Diagrams Electrical Diagrams PC Board Assembly Main Inverter Board PC Board Assembly Input Board Cutting Current Path SVM Error Reporting Form