Lincoln Electric SVM188-A Troubleshooting and Repair, PC Board Troubleshooting Procedures

Page 43

TOC

TOC

F-3

TROUBLESHOOTING AND REPAIR

F-3

 

PC BOARD TROUBLESHOOTING PROCEDURES

 

Return to Section

Return to Section TOC

TOC

Return to Master

Return to Master TOC

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 par ts.

CAUTION

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 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 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-shield- ing 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 prop- er failure analysis.

4.Test the machine to deter mine if the failure s y m p t o m h a s b e e n c o r r e c t e d by t h e 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.R e m ove t h e r e p l a c e m e n t P C b o a r d a n d s u b s t i t u t e i t w i t h t h e o r i g i n a l P C b o a r d t o 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 wir ing harness, junction blocks, and terminal strips.

Return to Section

Return to Master TOC

ATTENTION

Static-Sensitive

Devices

Handle only at

Static-Safe

Workstations

-R e m ove yo u r b o d y ’s s t a t i c charge before opening the static- shielding bag. Wear an anti-static wrist strap. For safety, use a 1 Meg ohm resistive cord connected to a grounded par t of the equipment frame.

-If you don’t have a wrist strap, touch an un-painted, grounded, part of the equipment frame. Keep t o u c h i n g t h e f ra m e t o p r eve n t s t a t i c bu i l d - u p. B e s u r e n o t t o touch any electrically live parts at the same time.

b. If the original problem is recreated by the substitution of the original board, then the PC b o a r d wa s t h e p r o bl e m . R e i n s t a l l t h e replacement PC board and test the machine.

6.A l way s i n d i c a t e t h a t t h i s p r o c e d u r e wa s fo l l owe d w h e n wa r ra n t y r e p o r t s a r e t o b e 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.

Return to Section TOC

Return to Master TOC

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

DC-600

Page 42 Page 44
Image 43
Page 42 Page 44
Contents DC-600 ISAFETYi Can be dangerous SafetyElectric Shock can kill Fumes and GasesFor Electrically Powered equipmentSûreté Pour Soudage a L’Arc Précautions DE SûretéElectromagnetic Compatibility EMC Safety Master Table of Contents for ALL Sections Table of Contents Installation Section Technical Specifications DC-600 InstallationElectric Shock can Kill Safety PrecautionsSelect Proper Location Electrical Input Connections Fuse and Wire SizesGround Connection Connection for Highest Rating Plate VOLTAGE, 50 or 60 HZ Reconnect ProcedureConnection for 440 Volts 50 or 60 HZ V 60HZ See Machine Rating Plate for Required Input Supply Voltage ELECTRODE, Work and #21 Lead Output ConnectionsConnections Terminal Strip 1 T.S.1 Auxiliary Power Control ConnectionsTerminal Strip 2 T.S.2 DC-600 Table of Contents Operation Section Operation Safety PrecautionsGeneral Description Design Features AdvantagesRecommended Processes and Equipment Output Control Output Voltage Current Meanings of Graphical Symbols on Case FrontOFF Input Power Welding CapabilityControls and Settings Meaning of Graphical Symbol for Ground CON- NectionOVERLOAD, OVERCURRENT, and Fault Protection Auxiliary Power in MS-RECEPTACLEWelding Procedure Recommendations Remote Control of Machine OperationOperating Steps Remote NA-3 Automatic Wire FeederLN-7 and Other Constant Wire Feeders LN-8 or LN-9 SEMI-AUTOMATIC Wire FeederDC-600 Table of Contents Accessories Section Field Installed Options AccessoriesWire Feeders and Tractors Factory or Field Installed OptionsFigure C.2 MULTI-PROCESS Switch Cable Connections Accessories Table of Contents Maintenance Section Safety Precautions Electric Shock can Kill MaintenanceRoutine and Periodic Maintenance 1TABLE of CONTENTS-THEORY of Operation Section E-1 Input Circuit and Main TRANS- Former Theory of OperationRectification Firing CIRCUIT, Control CIR- Cuit and RectificationFiring Board Thermal Protection SCR Operation DC-600 1TABLE of Contents Troubleshooting and Repair F-1 HOW to USE Troubleshooting Guide 2TROUBLESHOOTING and REPAIRF-2PC Board Troubleshooting Procedures Troubleshooting and RepairControl Feeder. See Protective Devices Check all three phase input Output Control J1,Pin2. See Wiring Diagram Wiring Diagram Test Description PC Board Troubleshooting GuideMaterials Needed PC Board Troubleshooting Guide Figure F.2 Control Board LEDs Control BoardDC-600 Internal Trigger Circuit Test Internal Trigger Circuit Test Procedure75 76 Internal Trigger Circuit TestDC-600 Firing Board Test Firing Board Test Control Board Test Figure F.7 Control Board Control Board TestMain Transformer Voltage Test Figure F.8 Input Contactor and Reconnect Panel Main Transformer Voltage TestFigure F.9 Transformer Secondaries Main Transformer Voltage Test Control Transformer Test Control Transformer Test ProcedureInput Contactor Test Voltage Test Input Contactor TestSCR Bridge Test SCR Bridge Test Anode Cathode Remove Insulating PaintActive Test Scope Settings Maximum Output Setting no Load Minimum Output Setting no Load 35TROUBLESHOOTING and REPAIRF-35 2V/Div Volts DC-600 Input Contactor CR1 CLEANING/REPLACEMENT Cleaning Procedure Input Contactor CLEANING/REPLACEMENT ProcedureContactor Replacement Procedure SCR Rectifier Bridge Removal and Replacement Procedure SCR Rectifier Bridge 42TROUBLESHOOTING and REPAIRF-42Removal and Replacement Procedure Removal ProcedureInsulator Lock Washer Plain Washer Output Snubber Lead Replacement ProcedureDC-600 Main Transformer and Choke Removal and Replacement Main Transformer and Choke Removal and ReplacementRemoval Procedure Weld Maximum Open Circuit Voltages Input Idle Amps and WattsDC-600 Table of Contents Diagram Section Electrical Diagrams Wiring Diagram 230/460/575 Volt Machines G3506-1 Schematic Complete Machine G3575 Schematic Control PC Board G3408-1 Control PC Board Assembly G3409-1 Schematic Firing PC Board G3741-1
Top Page Image Contents