Fault route

LGK100L Burns Filter-Board Fuse Diagnostic

A branch-isolation workflow for LGK100L machines that burn the filter-board fuse after power-on.

Quick Answer

When the LGK100L burns the filter-board fuse at power-on, the source workflow separates the filter-board fuse, fan branch and control-transformer branch by unplugging related connectors.

Use this page when

  • Filter-board fuse burns after power-on.
  • You can isolate branch connectors safely.
  • The goal is to locate which load branch overloads the fuse.

Do not use this page when

  • Input breaker trips before the filter fuse evidence.
  • The machine is completely dead without fuse burn.
  • Only the display is missing while fan works.
Diagnostic Panel

LGK100L filter-board fuse route

Isolate the branch that makes the fuse burn.

Filter-board fuse

Confirm correct fuse rating and actual burn symptom.

X3 branch test

Unplug X3; if fuse stops burning, diagnose that branch.

X5 branch test

Unplug X5; if fuse stops burning, diagnose that branch.

Fan branch

Fan fault can overload the related filter-board path.

Control transformer

Transformer fault can overload the other branch.

Fuse isolation table

Evidence pointExpected / abnormal evidenceRepair direction
Filter-board fuseFuse burns; source note refers to small normal fuse rating around 3A.Use correct fuse and isolate branch; do not oversize.
X3 connector unplug testFuse no longer burns after X3 is removed.Diagnose the load on X3 branch.
X5 connector unplug testFuse no longer burns after X5 is removed.Diagnose the load on X5 branch.
FanFaulted fan or branch load can burn fuse.Disconnect/measure fan branch.
Control transformerShorted transformer branch can burn fuse.Inspect transformer primary/secondary and wiring.

Next diagnostic step