Discussion Category:  Centrifuge

5424 restarting error

We are having an issue with our Eppendorf 5424. When we close the lid the screen flashes "5424"—as if it is restarting—then the lid opens again and the screen goes back to normal. There is no error message and the problem goes away briefly if we unplug the unit. Any thoughts?

Thanks!! 

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Asked by

krkoehle
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avatar placemarkReply by
medphysteo

I saw the same once 3yrs ago, and adjusted the lid switch actuator to "see" the lid closed sooner. I don't know if it ever recurred because the machine left the building a while later, but it seemed to fix it at the time.

Jeff

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avatar placemarkReply by
dkg

dear friend,

it seems 5volt supply is lowering as lid tries to close. there are two reasons

either lid is latch is loading the supply momentrily

or driver to the lid latch is troubling ang not able to supply the sufficient current to lid latch

dkgupta

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bernieballReply by
bernieball

Hi Jeff,

How is the lid switch actuator adjusted?

 

Bernie

 

Quote medphysteo

I saw the same once 3yrs ago, and adjusted the lid switch actuator to "see" the lid closed sooner. Jeff

 

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avatar placemarkReply by
medphysteo

Hi Bernie,

The lid sensor is a reed switch that is closed by a magnet attached to the lid. The reed switch can be adjusted up and down by loosening the two nuts that hold it in place. It's mounted in about the centre of the frame at the top where the lid comes down at the front.

There is also a latch position microswitch at the bottom of the left latch hook. Make sure it isn't loose and that the switch is closed when in the latch position.

To get to the whole mechanism you have to remove the lid and machine housing.

Jeff

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bernieballReply by
bernieball

The lid looks simple enough, but I'm guessing the 4 rubber feet have screws under them that attach the base to the upper housing.  Thing is, I can't figure out how to remove the rubber feet without destroying them.  I tried turning and then pulling them, but they don't seem to be coming off.

Any hints or manual pages?

Bernie

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avatar placemarkReply by
medphysteo

All four screws are on the top housing, two at the back and two at the front where the lid comes down, next to theslots where the latch hooks come out to grab the lid. The top cover is really snug so you might have to work a flat blade screwdriver around the seam to pry it up a bit at a time all around, but it will come up and after an inch or two will be free enough to lift off.

When you're taking the lid apart, after you have the top of it removed leave it in the open position to disengage the springs and take the hinge rod out, just makes it a bit easier with the tension off the springs. Then there's just one connector to the fan routed through a hole, if memory serves. I can email you more info if you like.

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bernieballReply by
bernieball

Thank you for your sage advice.  Following your directions I was able to remove the housing and get a look at everything.  I adjusted the reed switch upwards (it was already close to being all of the way up), blew out some dust, reassembled the housing, and gave it a test - it works like new.

Again, thank you for all of your help.

Cheers, Bernie

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avatar placemarkReply by
medphysteo

You're welcome, glad you got it going.

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