Iris driver cannot maintain the resquested voltage

Hi everybody,


We have a GC 7890A with a 7000 triple quad MS.

Lately we have cleaned the source as usual and we have obtained a not so good result with the autotune (counts for both analyzer and all ions five time lower than before the cleaning).

The extractor lens wire (brown cable) was stuck between the end of the column and the source inlet. The cable protection has been damaged but we put the cable back in place. After that, it was impossible to get through an autotune without getting an error message.

We ordered and installed a new brown cable but it's still impossible to finish an autotune. It turns off more or less quickly and we get the message "Qqq fault detected : 3.3 iris driver cannot maintain the requested voltage".


Have you ever got this kind of error message? what can I check to find the source of the problem ?


Thanks for your help


  • Hi,


    this fault is caused by the Iris lens of the TripleAxis Detector.

    Could be the end of clip that holds EM horn is shorting to iris lens.

    Reinstall the multiplier and check the iris lens is not shortet to ground.




  • Hi Fanny,

    Just Checking if your issue is rectified?





  • Hi,


    Thank you for your replies.


    We had some assistance by email from Agilent and we checked several points.

    We changed the EM horn and cleaned the HED. The clip that holds EM horn seemed to be fine.

    We also ran several tests from the Lab device toolkit and the power supply test, the ramp filament DC L1 test and the ramp MS2 shroud lens L16 test failed.

    We are now wondering if the problem is caused by one of the electronic cards and we are waiting for a service engineer that should be here in the next weeks.



  • I also am having this issue, did it end up being one of the cards?

  • Hi,


    we don't know for sure as we haven't had the opportunity to change the cards or the iris block yet (due to the worldwide travel restrictions).

    We had an online support and our system no longer shows this error as the Agilent engineer told us to change the iris value from "dynamic" to "0" and to save the tune file with this setting. We can't do an autotune with this setting but a quicktune is possible.

    We can at least analyze samples but we have lost sensitivity and we have a bad detection for mass around 502.



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