defective limit switch for the autosampler?

[xiaoyu_fish]

Hi,

We have a Thermo Finnigan LCQdeca with Surveyor autosampler. However, the autosampler could not be initiated. It keeps showing two error messges: Error 537067527: Unable to find home fly when expected; Error 537067546: Mechanical failure detected. Meanwhile, the syringe driver makes a loud buzzing sound. I checked the needle assembly, transfer line and the injection valve, sample loop. I have made sure there is no blockage. So, is there possibly a defective limit switch? Or due to other reasons? If we want to replace that, anybody has more information about that item? Any suggestion will be greatly appreciated.

[lmh]

if there's no blockage, it is worth checking that the screw that drives the syringe plunger up and down is able to turn reasonably freely. It has a screw-driver slot on one end that you can use to check it turns. If you are lucky, you may have a simple fault like a dirty screw-thread making it too stiff for the drive system, but last time I had very loud noises from this unit, it was dead.

[xiaoyu_fish]

Thank you very much. I will check that. Just ordered the lead screw grease.

[xiaoyu_fish]

Thank you so much, Imh. That is the exact problem. After I cleaned and lubricated the lead screw on the syringe drive, there are no more error messages and loud buzzing sound now.

[lmh]

oooh, you've made me all happy! Glad it was something simple.
Li