Repair Case

Plasma Cutter No Pilot Arc

Use this page when a plasma cutter powers on but cannot establish a pilot arc at the torch.

Separate these faults

SymptomLikely areaNext check
No gas and no HFTrigger/logic/control supplyCheck torch switch and control rails
Gas flows but no HFHF start board or trigger to HF boardCheck spark gap, HF transformer and drive signal
HF present but no pilot arcTorch consumables or pilot current pathCheck electrode/nozzle and pilot resistor/path
Pilot exists but no transferWork clamp, arc-transfer sensing or main current pathCheck clamp, output rectifier and feedback

Safety note

HF start circuits can produce painful high voltage and can damage meters. Use proper probes, insulation and discharge procedures.

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