Lincoln Electric SVM100-A service manual Function Problems

Page 48

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F-7

 

TROUBLESHOOTING & REPAIR

 

 

 

TROUBLESHOOTING GUIDE

 

 

Observe Safety Guidelines

 

 

 

 

 

 

 

 

 

 

detailed in the beginning of this manual.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PROBLEMS

 

POSSIBLE AREAS OF

RECOMMENDED

 

 

(SYMPTOMS)

 

 

 

MISADJUSTMENT(S)

 

 

COURSE OF ACTION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FUNCTION PROBLEMS

 

 

 

 

 

 

 

The yellow light (PL1) on the front

 

 

1. Normal condition - this light

 

 

 

 

 

 

 

panel is not lit.

 

 

 

will glow only if machine is in

 

 

 

 

 

 

 

 

 

 

 

 

an overheated condition.

 

 

 

 

 

 

 

 

 

 

 

 

(Thermal overload).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

One or more keypad lights (LEDS)

 

 

1. Be sure that the proper weld

 

 

1. Check the Keypad LED board

 

 

 

are dark and cannot be lit when

 

 

mode is selected. For

 

 

to the Control board harness.

 

 

 

their respective keys are pressed -

 

 

example, the high frequency

 

 

The plugs may be loose or

 

 

 

machine is operable.

 

 

 

keys and keypad lights

 

 

defective.

 

 

 

 

 

 

 

 

(LEDS) are not active in the

 

 

2. If only one red LED won’t light,

 

 

 

 

 

 

 

 

stick mode.

 

 

 

 

 

 

 

 

 

 

 

 

 

the LED PC Board may be

 

 

 

 

 

 

 

 

 

 

 

defective. Replace.

 

 

 

 

 

 

 

 

 

 

 

3. If three or more red LEDS do

 

 

 

 

 

 

 

 

 

 

 

not light, the Control board may

 

 

 

 

 

 

 

 

 

 

 

be faulty. Replace.

 

 

 

 

 

 

 

 

 

 

 

 

 

The Beeper (Piezoelectric Buzzer)

 

 

1. Background noise may be too

 

 

1. Watch the Control Panel

 

 

 

cannot be heard - machine operat-

 

 

loud for user to hear beeper.

 

 

Display to see if the keys are

 

 

 

ing normally.

 

 

 

 

 

 

responding properly to key

 

 

 

 

 

 

 

 

 

 

 

presses. If so then the Buzzer

 

 

 

 

 

 

 

 

 

 

 

may be defective. Replace the

 

 

 

 

 

 

 

 

 

 

 

Piezo Electric Buzzer. HINT-

 

 

 

 

 

 

 

 

 

 

 

The Piezo Electric Buzzer

 

 

 

 

 

 

 

 

 

 

 

may be checked by applying

 

 

 

 

 

 

 

 

 

 

 

a 9vdc signal to the buzzer

 

 

 

 

 

 

 

 

 

 

 

leads. Red lead to +. Black

 

 

 

 

 

 

 

 

 

 

 

lead to –.

 

 

 

 

 

 

 

 

 

 

 

2. The Control board may be

 

 

 

 

 

 

 

 

 

 

 

faulty. Check for the presence

 

 

 

 

 

 

 

 

 

 

 

of 15vdc at pins 6J6 to 13J6 at

 

 

 

 

 

 

 

 

 

 

 

the Control board. See figure

 

 

 

 

 

 

 

 

 

 

 

at end of this Guide. The 15vdc

 

 

 

 

 

 

 

 

 

 

 

will be present for a very short

 

 

 

 

 

 

 

 

 

 

 

period of time when a key is

 

 

 

 

 

 

 

 

 

 

 

pressed. If the voltage is not

 

 

 

 

 

 

 

 

 

 

 

present then replace the

 

 

 

 

 

 

 

 

 

 

 

Control board.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CAUTION

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 troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

SQUARE WAVE TIG 255

Image 48
Contents Square Wave TIG Safety Electric Shock can killARC Rays can burn Fumes and Gases can be dangerousCylinder may explode if damaged Welding Sparks can cause fire or explosionElectric and Magnetic Fields May be dangerousPrécautions DE Sûreté Sûreté Pour Soudage a L’ArcMaster Table of Contents for ALL Sections Table of Contents Installation SectionInstallation Technical Specifications Square Wave TIGSafety Precautions High Frequency Interference ProtectionSelect Suitable Location StackingInput Connections Ground ConnectionInput Supply Connections Reconnect Procedure Output ConnectionsTIG Torch Connection Table A.1 Stick Electrode Cable ConnectionOperation Section Operation Operating InstructionsGeneral Warnings Fumes and GasesSection TOC Polarity Do not Switch AC & DC Recti Fier Power Source While Weld ING TIG Gtaw Single PhaseWork Connec Coolant Tion OutputDesign Features Advantages Operational Features and ControlsGeneral Description Recommended Processes and EquipmentWelding Capability LimitationsControls and Settings Control Panel KeysCase Front Controls LoadAccessory Operation TIG Welding Table B.1 Recommended Polarity Settings for TIG WeldingHand and Foot Amptrol Welding Operation TIG Welding GuidelinesTIG Welding Sequence Operation 2-STEP Mode Table B.2 Typical Current Ranges 1 for Tungsten ElectrodesSquare Wave TIG 255 12/95 TIG Welding Sequence Operation 4-STEP Mode Auxiliary Power Advanced TIG Welding FeaturesALL Machines AC Wave Balance and Auto BalanceOverload Protection Square Wave TIG Accessories Section Accessories Options / AccessoriesInstallation of Field Installed Options Undercarriage FunctionMaintenance Section Maintenance MaintenanceRoutine and Periodic Maintenance Safety PrecautionsFigure D.1 General Assembly Exploded View Square Wave TIG Power Supply Block Logic Diagram Theory of Operation SectionTheory of Operation Input Line Voltage and Main TransformerOutput Rectification and Feedback Control High Voltage / High Frequency Circuit DC Welding Output DC Welding CircuitAC Welding Output AC Welding CircuitSCR Operation SCR Operation Square Wave TIGThermal Protection Troubleshooting & Repair Section 1TROUBLESHOOTING & Repair HOW to USE Troubleshooting GuideTroubleshooting & Repair PC Board Troubleshooting ProceduresTroubleshooting Guide Output Problems12/95 Square Wave TIG Troubleshooting & Repair Problems Symptoms Possible Areas of MisadjustmentsRecommended Course of Action Function Problems Troubleshooting Guide Troubleshooting & Repair TIG Mode Problems Troubleshooting & Repair Troubleshooting Guide TIG Welding Problems Troubleshooting & Repair Stick Welding Problems PC Board Connector Locations Figure F.1 Control Board ConnectorsControl Transformer T2 Voltage Test Test DescriptionMaterials Needed Test Procedure Control BOXControl Transformer T2 Voltage Test Figure F.4 Control Board and TransformerPROTECTION/SNUBBER Board Continuity Test PROTECTION/SNUBBER Board Continuity Test Figure F.6 PROTECTION/SNUBBER Board Test Points Table F.6 Square Wave TIGARC Start Trigger Circuit Test ARC Start Trigger Circuit Test Figure F.9 PROTECTION/SNUBBER Board Test Points Static SCR Test Static SCR Test Figure F.11 Protection Board Plug LocationsActive SCR Test Active SCR Test Figure F.13 PROTECTION/SNUBBER Board Plug LocationsBattery Test Silicon Controlled Rectifier TestNormal Open Circuit Voltage Waveform DC Stick Mode Scope SettingsNormal Open Circuit Voltage Waveform AC Stick Mode Normal Open Circuit Voltage Waveform DC TIG Mode Normal Open Circuit Voltage Waveform AC TIG Mode Typical Output Voltage Waveform Machine Loaded DC TIG Mode Machine Loaded to 200 Amps AT 50 VDCAC TIG Mode Auto Balance on Machine Loaded to 50 Amps AT 26VACMachine Loaded to 200 Amps AT 46 VAC Volts 5ms Typical SCR Gate Voltage WaveformVolts 2ms Troubleshooting & Repair FAN Motor and Blade Removal Tools RequiredFAN Motor and Blade Removal SCR Heat Sink Assembly Removal Materials RequiredSCR Heat Sink Assembly Removal Retest After Repair Input Idle AmpsRecommended Meters for Machine Output Tests Retest After Repair cont’d Figure F.16 Transformer Lead Test PointsElectrical Diagrams Electrical Diagrams Control Board G2150 PTC1,PTC2 THERMISTOR-PTC,56 OHMS,90MAControl Board G2150 cont’d Square Wave TIG PROTECTION/SNUBBER Board L9255 CAPACITOR-CEMO,4700P,50V,10% Square Wave TIG Wiring Diagram Square Wave TIG Machine Schematic Square Wave TIG 6 a 0 a 7 a 8 a 3 CG2150 A C C TControl Board Schematic Square Wave TIG 255 cont’d G2150 Y P a DPROTECTION/SNUBBER Board Schematic Square Wave TIG 255 L9255 Keypad LED Board Square Wave TIG 255 L9212