G1314F VWD intensity failed

I have tried two new lamp and its all fail intensity test on the controller. Then I borrow a standard flow cell from another LC and I got min. intensity pass but fail average intensity. So I use Methanol to clean the flow cell window and flush the flow cell with methanol using syringe and then flush it with water using syringe. Then I got min intensity pass but fail average intensity, So that's prove the flow cell was part of the issue. 

    To save me time to look for manual or googles any forum or blog, suggested by my workmates, open the optical unit. clean all mirrors and lenses with methanol, but then I now got everything fail and the intensity was a lot worse, the minimum intensity only have 217.

   I was a bit skeptical about the solvent as I would think that could introduce contaminant or residue when you expect an clean and clear optical path, just like a mass spec.

senior one told me than methanol have dissolve the shiny bits of the mirror. we need to order the whole optical unit.

I then open the optical unit and rub it with clean dry cloth, of course lint free.

min.i intensity becomes 954 but nowhere near to >6400.

Is there anything I could do or try and rescue it? I broke it, and I want to fix it. I have been thinking day and night and hope anyone give me some idea?


  • Since 2019, the only supported repair (for trained field service engineers) on the optical unit is replacement of the source lens assembly. Any work inside the optical unit is not supported. Cleaning the mirror/grating was never be considered to be a repair procedure. Even the manual from 2011 says "Contaminated mirrors and the grating result into a replacement of the optical unit."

    Therefore, the only way to get this fixed is replacement of the optical unit. If that's too expensive (having the age of your G1314F in mind), you can ask for a quote for a pre-owned, refurbished and tested G7114A or G7114B.

  • Sorry for such a late reply. I was busy fixing other stuff. You were right. I have done some research and find out on G1314A/B/C, it suggested only to clean the lens assembly inside the optical unit. Grating and the mirrors are supposed not to be cleaned, or even touch with dry cloth. The mirrors coated with magnesium fluoride so it will make sense not to clean as the solvent would have dissolve this coating and the mirrors lost its capability of reflecting lights. In G1314F manual already suggest not to repair anything inside optical unit but to replace the whole thing. 

    in the end my boss has ordered whole optical unit and I replaced it. 

    I would like to know if I replaced the mirrors inside the G1314F optical unit will I get it working again. Unfortunately that unit has to be sent back so no experiment I could try :(

  • When it comes to repairs on the optical unit, there are no differences between the three generations of VWD G1314A/B/C, G1314D/E/F and G7114A/B; so it's mainly the source lens and the D2-lamp.

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