FLD: emission encounter index calculation failed (init-phase)

I think we'd need some more details. How old is the FLD? What's the model number? Does it have latest firmware? Is there a lot of dust in the lab?

Very likely the entire EM monochromator assembly needs to be replaced. You cannot replace the encoder, grating or motor only. This is something that needs to be done by an Agilent service engineer.

I think the FLD and the whole system are around 12 years old. 

The latest firmware is A.06.33[001]

Yes, the lab is dusty.

The model number is G1321B serial# DEABO01273

Thanks for your answer.

Yes, the FLD got manufactured in 2011. Very likely the instrument needs a new Emission monochromator. There is something wrong with counting the lines on the encoder wheel. Cleaning that area might help, but also needs to be carried out by an Agilent service engineer. This is a time consuming task, I don't think it's any cheaper and there's no guarantee that the issue you see, gets fixed by that. Even if it does, you still have an old monochromator assembly.

Yes, the FLD got manufactured in 2011. Very likely the instrument needs a new Emission monochromator. There is something wrong with counting the lines on the encoder wheel. Cleaning that area might help, but also needs to be carried out by an Agilent service engineer. This is a time consuming task, I don't think it's any cheaper and there's no guarantee that the issue you see, gets fixed by that. Even if it does, you still have an old monochromator assembly.

Thanks