Door lock switch failure

Lucas,

  I cannot speak to this specific model number, but we were having a high incidence of the same failure with two identical Sorvall ST-40's, the failure was caused by the lab personnel 'slamming' the lids, despite of the 'auto-latch' function of the ST-40 lid.

  The slamming action of the operators caused the locks to shift mechanically, to the point where the unit would no longer latch, preventing the centrifuge from running. It took some time to break their bad habit, but if your Sorvall has an auto-latching lid, you will have to make sure there isn't some unknown associate on night shift that is 'reportedly' still slamming the lid. Good luck.

Sincerely,

Martin J Winebrenner, CBET

Have you tried adjusting the latch claws on the lid? 

I was getting this same issue with a different model centrifuge so I adjusted the latch claws so that they were shorter. I did one full rotation on each claw and this seemed to solve the issue. 

DISCLAIMER: Proceed at your own risk. The latch claws are factory set. Thermo recommends that no such adjustments are needed but when damage is caused to the locking mechanism (most likely by slamming the lid), this is one small way to tweak it and get more time out of it.