Board reference

LGK60L Main Control Board Connector Reference

A board-level reference for LGK60L control-board connectors and service evidence.

Quick Answer

The LGK60L main control board is the low-voltage decision layer. It links phase-loss protection, O.C indication, cutting current command, voltage/current feedback, DC24V output, drive output, overcurrent input and temperature relay evidence.

Use this board reference after confirming input power and control-transformer supply.
X16 fan / DC24V evidence and X17 AC15V-0V-15V evidence are key for fan and control-power faults.
Do not replace the main control board before separating thermal relay, phase-loss and fan-load evidence.

Use this page when

You are tracing LGK60L fan, O.C light, control power, drive or feedback symptoms.
The machine has enough power for control-board connector checks.
You need to map symptom to connector/function layer.

Do not use this page when

The machine trips the breaker before control power appears.
You only need a generic plasma-cutter operation explanation.
You cannot safely access charged inverter circuitry.

Service map

LGK60L main control-board service map

Read the board by function: input rails, protection inputs, command inputs and drive outputs.

Dual AC15V input

Control-board low-voltage supply evidence; abnormal rails can mimic many board faults.

Phase-loss protection

O.C light can be triggered by missing phase or false phase-loss detection.

Cutting potentiometer

Current command path; bad potentiometer can cause unstable or missing current command.

Voltage / current feedback

Feedback layer for output regulation and current display/decision behavior.

Drive signal output

PWM/drive permission toward upper power stage and overcurrent input feedback.

Temperature relay

Thermal protection path; unplug tests can separate relay from board decision.

Connector and symptom evidence

Board evidence	Related symptom	First direction
X16 DC24V fan/output path	Fan not running	Disconnect fan and confirm board-side DC24V before replacing the fan.
X17 AC15V-0V-15V input	Fan/control abnormal, no control response	Check control transformer and wiring before replacing main board.
Phase-loss protection input	O.C light on after power-up	Separate real phase-loss from phase-loss circuit false trigger.
Temperature relay input	O.C/protection indication	Unplug thermal relay path to see whether indication clears.
Voltage/current feedback	Current unstable, weak output, wrong response	Check feedback path before current-control board replacement.
Drive output / overcurrent input	No cutting output or O.C under trigger	Check overcurrent feedback and downstream drive board/power stage.

Next diagnostic step

LGK60L fan not runningUse X16 and X17 evidence to separate fan and control board faults.LGK60L model referenceReturn to full board-stack routing.LGK control power railsCompare AC15V, DC24V and board-level supply paths.