Board reference

LGK60L HF Arc-Start Board Reference

A service map for LGK60L high-frequency start, gas control and arc-start cutoff diagnosis.

Quick Answer

The LGK60L HF arc-start board links torch switch, gas-valve control, high-frequency supply, high-frequency arc-start and arc-start cutoff. This is the page to use when the machine has gas/HF timing issues rather than a simple no-power fault.

Gas always on, no gas, HF always on and HF does not transfer are different control states.
Separate gas-valve socket, torch-switch input and high-frequency supply before replacing the HF board.
Arc-start cutoff is important: HF should not continue after normal arc transfer.

Use this page when

LGK60L has gas or HF symptoms.
Torch trigger produces some response.
You need to decide between gas valve, torch switch, HF supply and HF board.

Do not use this page when

Machine is fully dead.
Fan/control-power fault is the only symptom.
Input breaker trips immediately.

Service map

LGK60L HF board functional route

Use the HF board as a gas/trigger/start-cutoff service layer.

Torch switch input

Trigger signal enters the HF/control path before gas or HF actions.

Gas-valve socket

Controls solenoid output; distinguish no gas from always gas.

HF power input

Supplies high-frequency start energy to the arc-start section.

HF arc-start

High-frequency path should appear during start, not necessarily during normal cutting.

Arc-start cutoff

If HF continues after arc starts, diagnose cutoff/feedback path.

HF board fault evidence

Symptom	Likely board layer	Repair direction
Power-on gas flow	Gas-valve output stuck or control signal stuck	Separate solenoid valve from HF board command.
Press torch, no gas	Torch switch, gas-valve socket, solenoid coil or control input	Check trigger input and gas-valve supply path.
Power-on HF	HF control stuck on	Inspect HF relay/control section and cutoff logic.
HF remains after arc starts	Arc-start cutoff failure	Check transfer feedback and cutoff path.
Gas and HF present but no arc	HF may not be the root fault	Move to output current, work return, torch consumables and main output path.

Next diagnostic step

LGK60L model referenceOpen full board-stack and symptom routing.LGK100L no outputCompare no-output split on a larger plasma-cutter platform.WSM-315 HF boardCompare TIG HF start-board logic.