Fault route

LGK100L Weak Cutting Current Diagnostic

A current-too-small diagnostic route for LGK100L plasma cutters using external connection, command, feedback and shunt evidence.

Quick Answer

For LGK100L weak cutting current, split external output connection, current potentiometer, Hall sensor feedback, shunt/middle-board contact and main control board evidence.

Loose torch/output/work connections can appear as weak current.
A bad potentiometer or Hall sensor feedback path can make current command/feedback wrong.
Poor shunt contact or middle-board issue should be considered before replacing the main control board.

Use this page when

Cutting current is weak or welding/cutting current is small.
Machine powers up and output exists but is insufficient.
You need to decide between external output, potentiometer, Hall feedback, shunt and board faults.

Do not use this page when

There is no output at all.
Breaker trips at power-on.
IGBT is visibly burned.

Diagnostic Panel

LGK100L weak-current route

External connection first, feedback and shunt evidence before board replacement.

Output connection

Torch connector, electrode holder/tungsten clamp and work lead must be tight.

Current potentiometer

Open or poor contact can limit current command.

Hall sensor feedback

Check DC15V, -DC15V and signal line behavior.

Shunt / middle board

Poor shunt contact or middle-board fault can reduce current evidence.

Main control board

Replace only after external, command and feedback evidence are checked.

Weak-current evidence table

Evidence point	Expected / abnormal evidence	Repair direction
Output cable / torch connector	Loose connector or poor work return reduces real current.	Repair mechanical connection first.
Current potentiometer	Open or bad contact changes current command.	Replace potentiometer if unstable/open.
Hall sensor connector	Expected DC15V/-DC15V supply and signal behavior at X14-style feedback path.	Inspect/replace Hall sensor and wiring.
Shunt / middle board	Poor contact or middle-board fault affects current detection/current path.	Repair contact or replace middle board if proven.
Main control board	All external/feedback evidence normal but current remains weak.	Main control board becomes suspect.

Next diagnostic step

LGK100L no outputUse if weak current becomes zero output.Hall current sensorUse feedback evidence before board replacement.LGK100L control boardOpen connector map and Hall feedback reference.