Please let us know the detector parameters that you are using. In most cases the issue is with the Jet. Jets are hard to clean properly and the replacement should be the next step.
Air 400 ml/min
H2 40 Ml/min
Makeup, with today's detectors you do not need much, 5 to 10 ml/min if needed at all.
Temperature 300 C
If it doesnt light with the above change the jet, check the column connection for leaks.
Thanks for your valuable response & support. i'll try it .
I had the same Problem.
I just changed the N2 Makeup Gas from 35 to 25. 11 you will loose so u get 14 at the detector.
Agilent recommend these settings too. Air to H2 supposed to be 1 to 10.
Check on the top of your device if it glowing while it say " ignition".
Also you can hear the igniting sound.
You can also check the outcome of your column. Just activate the flow and check with a glass of water at the end of the column if you see small bubbles.
Hope I can help