Fault route
TIG Torch Switch No Response Diagnostic
A general TIG trigger-input route for machines where pressing the torch switch produces no gas, HF or current response.
Quick Answer
When pressing the TIG torch switch produces no response, diagnose the trigger input before gas, HF or output stages. Check switch contacts, torch connector, 2T/4T mode logic and control-board trigger input.
Diagnostic path
Torch switch → torch connector → trigger input line → 2T/4T logic → gas pre-flow command → HF/current sequence.
Evidence table
No gas/no HF/no current: trigger input or mode logic first. Gas works but no HF: use HF missing route. HF/current starts wrongly: use timing route.