Can't open centrifuge - Eppendorf centrifuge microcentrifuge 5414 micro tubes

you are right, there is no manual, except for the 5420. Try here, they do Sales and Service as well

https://www.gmi-inc.com/product/eppendorf-5402-refrigerated-centrifuge/

and you can still buy them

https://angelusmedical.com/products/eppendorf-5402-refrigerated-micro-centrifuge-parts-only

Did you ask them direct for support? Did you open it up and check Ribbon Cable connections?

Centrifuge and Rotor Service

Eppendorf https://www.eppendorf.com > ca-en > service-support
epServices offers rotor assurance plans. Read more about the professional inspection services and evaluation of centrifuge rotors and buckets.

Service & Support

Eppendorf https://www.eppendorf.com > ca-en > service-support
The services range from technical support and troubleshooting to delivery of replacement parts on short notice and customer-specific maintenance programs. ULT ...

Service & Support

Eppendorf https://www.eppendorf.com > your-centrifuge-solutions
We provide efficient, reliable services for your centrifuge. Our ... Includes a full annual preventive maintenance service program for assured instrument ...

If the lid of your Eppendorf centrifuge model 5702 is not latching or locking closed after the emergency release, it is possible that the locking mechanism is damaged or misaligned. Here are some steps you can try to troubleshoot the issue:

1. Check the alignment of the lid: Make sure that the lid is properly aligned with the base of the centrifuge. If it is not, the locking mechanism may not engage correctly. Adjust the lid as needed and try to latch it closed.
2. Inspect the locking mechanism: Check the locking mechanism on both the lid and the base of the centrifuge for any signs of damage or wear. If you see any damage, you may need to replace the locking mechanism.
3. Check the safety interlock switch: The safety interlock switch is a small button located on the base of the centrifuge that is depressed when the lid is closed. If this switch is not working correctly, it can prevent the lid from latching closed. Check that the switch is functioning properly by pressing it with a small tool while attempting to latch the lid.
4. Contact Eppendorf customer support: If none of the above steps work, you may need to contact Eppendorf customer support for further assistance. They can help you troubleshoot the issue and provide advice on how to proceed.

I know nothing about the device, but it reads like you forced the door into a wedged position and it's stuck there. I would gently pry at it to get it past the "wedge", then study the mechanism to see whether the actual latch is broken, or just out of position.

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The centrifugal switch inside has gotten dirty, or else the start capacitor is disconnected or faulty. It's about time to open that grinder up and examine the centrifugal switch. If it's working OK, then examine the capacitor connections. If they look OK, replace the capacitor.

Probably too late now but there is usually a small hole in the centrifuge where a thin shafts can be inserted to manually disengage the locking system.

Anything with an IC can quit working. Also a motor that quits working can still have continuity if it isn't tested right giving false readings. I wonder if you can prove that the motor works by giving it power through test leads and if it needs temporary power to a start winding do so. If it has a centrifugal switch i would suspect it. Open the centrifugal switch and clean the contacts and verify that it opens and closes.

It's a centrifugal switch. if there are 4 contacts then it is like 2 switches that are normally open. No schematic is necessary. You can easily take apart, clean, re-bend etc many centrifugal switches... or just replace them with a new one.

Wikipedia says: A centrifuge is a piece of equipment, generally driven by an electric motor (some older models were spun by hand), that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis. A centrifuge is also used to separate the components of blood in blood banks.The centrifuge works using the sedimentation principle, where the centripetal acceleration causes denser substances to separate out along the radial direction (the bottom of the tube). By the same token lighter objects will tend to move to the top (of the tube; in the rotating picture, move to the centre).

Sounds as if the motor centrifugal switch is stuck. Check to see if lint built up around switch or centrifugal mechanism on motor shaft. Rap switch with the handle of a screw driver hard but don't break it .

sound like your even heat board has gone out / send me the complete model number from the panel inside the door and i will see if i can help out / larryyb