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Start from the visible symptom
Welder Faults
Use Faults when you only know what the machine is doing: no output, breaker trip, protection light, no HF, no gas, no wire feed, weak current or burned power devices. Faults pages are symptom entry points. They should guide you to the right Diagnostics workflow, model hub, board reference, circuit path or tool.
Start here by symptom group
Choose the visible behavior first. If you already know the exact model and measurement point, go directly to Diagnostics or Boards.
Arc start Gas, HF or no-output start problems For gas works but no HF, HF present but no current, no arc transfer and HF stuck on.
Power stage Breaker trip, IGBT/MOSFET or rectifier failure For burned devices, repeated device failure, rectifier bridge faults and output-diode problems.
TIG TIG torch, gas, HF, post-flow and current control For TIG-specific torch switch, 2T/4T, HF, foot pedal and current-command symptoms.
MMA / Stick Small inverter welder power, protection and no-output faults For compact ZX7-style machines with relay, fan, protection, MOSFET or weak-current faults.
Faults is for
Generic visible symptoms before a specific model is known.
Symptom landing pages that route to multiple Diagnostics.
Search-entry pages such as “welder no output” or “TIG no HF”.
Helping users choose the correct repair workflow before opening the machine.
Need repair steps? Open Diagnostics after choosing the symptom group. Know the machine model? Open Models and use the model hub.
How this section relates to Diagnostics
Faults are symptom entry pages. Diagnostics are the step-by-step workflows. A general symptom like “TIG no HF” can route to WSM-315 no HF arc start, TIG gas flows but HF missing, CT-312 gas clicks no HF no arc, or WSE AC/DC timing pages depending on the machine and evidence.
Power, protection and input symptoms Start here for machines that are dead, trip breakers, show protection light, or burn power devices.
Power Device Failure Index IGBT, MOSFET, rectifier bridge, output diode and repeated failure routes. ZX7-160/200 Dead No Power Bottom-board bridge, relay/start path, DC bus and auxiliary checks. ZX7 Breaker Trip / MOSFET Short DC bus short, MOSFET, driver transformer and output-load evidence. LGK100L Breaker Trip Rectifier bridge, filter capacitors, IGBT and driver board. CT-312 Protection in All Modes Shared inverter, thermal, feedback and output-stage evidence. MIG200DL Power-On Breaker Trip Rectifier bridge, bottom-board filter capacitors and inverter-board burn evidence. No output, weak current and current-control symptoms Use these when the machine powers up but output is missing, weak, unstable or not adjustable.
ZX7 Indicator On, No Output Top-board drive, transformer, output diode, shunt and feedback route. ZX7 Weak Current / Cannot Adjust Current command, shunt feedback, reactor and output cable checks. LGK100L Weak Cutting Current Output connection, current potentiometer, Hall feedback and shunt evidence. MIG200DL Unstable Welding Current Potentiometer, output cable, contact tip and board follow-up. WSM/WSE Current-Control Faults Panel command, feedback path and output-stage response. TIG Foot Pedal / Remote Current Fault Remote selector, pedal switch, potentiometer and command input. TIG gas, HF and start-sequence symptoms Use these when the visible problem is torch response, gas flow, high-frequency start, arc transfer or post-flow timing.
TIG Welder Fault Index Torch switch, gas solenoid, HF, 2T/4T, post-flow and current routes. TIG Torch Switch No Response Switch contacts, connector, 2T/4T logic and trigger input. TIG Gas Flows But HF Missing HF command, relay, HV pack and arc-start output. TIG HF Stuck On Arc transfer, HF command cutoff, relay/contact and feedback path. TIG Post-Flow Missing Panel post-flow, torch release logic, timing and gas output. Pre-Flow + HF Works, No Current PWM/current permission, driver stage, output path and feedback shutdown. MIG, wire-feed and gas-valve symptoms Use these when the problem is trigger response, gas valve, wire-feed output or MIG-specific no-output behavior.
MIG200DL Fault Index Display, fan, trigger, gas, wire feed, breaker and current routes. MIG200DL Trigger But No Gas External gas, P17 DC24V, gas valve and power board path. MIG200DL No Wire Feed P14 feeder output, motor and control path. MIG200DL Wire Feeds Continuously Stuck P13 input or P14 feeder output route. MIG200DL Trigger But No Output P12, P11/P16, P1/P2 and output connection route. MIG200DL Wire-Feed / Gas Control P13, P14, P17 signal and output split. Plasma and combo-machine symptoms Use these when the machine is a plasma cutter or a combo MMA/TIG/plasma unit such as CT-312 or LGK.
LGK Plasma Cutter Fault Index LGK60L and LGK100L gas, fan, protection, no-output and IGBT routes. CT-312 Repair Index MMA/TIG/plasma mode routing and board-layer diagnosis. CT-312 Plasma No Arc, Air Works Mode switch, HF/pilot start, shared output, torch and work return. CT-312 MMA Works, TIG/Plasma Fail Mode switch, gas/HF support and process-control path. LGK60L Trigger No Gas Torch switch, gas socket and solenoid route. LGK100L No Output Control, Hall feedback, diode, capacitor and IGBT split.