Thermal protection

Last week I had the thermal protection kick in, good thing as I could have come home to a burnt out house…I have a bit of time to look at it now so nozzle all cleaned up but it looks like I have killed my bed, any idea how to test it apart from the obvious one ie pre heat


-15 means that the line is receiving 0. So maybe the thermistor is defective or its wire is cut somewhere. It happens sometimes because of the movement of the bed.

Looks like I will strip it down to see if it’s a (fingers crossed) dodgy connection, thanks

Wires have come apart and the tape was loose so they just pulled out, is this an easy fix or do I just change them?

It looks like they just push back into the sleeve but not sure if it should be soldered or not as the end looks clean



It’s repairable, but those are fairly inexpensive, personally I would just replace it.

Are they brand specific or do I just use a one that looks the same?
Not sure where to even look?

Those are regular 100k NTC 3950 thermistors. Very easy to find and cheap (~ 1$). Take one with a long cable. You can also try to solder your broken thermistor, but it is a good idea to change it in case it is damaged as suggested by @CBoismenu. I always have some spare, just in case.

As andrivet said, they are repairable, however you have to ask, why did it break?
Was it poor manufacture?
Was it flexing on the cable? (this is my bet)
is there any weakness in the surrounding wire that will fail if you repair it?
The question of weather or not you should repair the wire really is dependent on how long it will take to get a replacement.
If it’s gonna take a while to get the replacement, do the repair and replace it when the spares arrive.
I’ve broken 3 so far, so carry a few spares for that reason.
The most common cause is the wire flexing tight in the same place as the bed moves back and forth.
It might pay the check the wire flex an potentially change the way the cable is attached to reduce the single point bending as much as possible.
This reduce my failure rate quite a bit.

Hi Ray, Looks like poor manufacture tbh as it split under the shrink wrap with a clean cut.
I ended up ordering a replacement (plus spares) from amazon which arriced today…took a longer to feed the cable back into the coiled protector sheath than it did to strip it and replace :slight_smile:
I have left a bit more slack on the replacement to make sure there are no tight spots…time will tell.

This happened to my bed’s thermistor, too. I ended up buying a 5 pack of thermistors made for the Ender 3 on Amazon for $8. While the wiring was super long, it did the job and now I have spares!

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