# MINTEMP E1 error testing rebuilt toolhead

**URL:** <https://forum.lulzbot.com/t/mintemp-e1-error-testing-rebuilt-toolhead/26712>\
**Category:** General\
**Created:** [May 30, 2024, 6:59pm UTC](https://forum.lulzbot.com/t/mintemp-e1-error-testing-rebuilt-toolhead/26712 "2024-05-30T18:59:22Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mhristau](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/mhristau/32/9696_2.png) [@mhristau](https://forum.lulzbot.com/u/mhristau)\
**Post date:** [May 30, 2024, 6:59pm UTC](https://forum.lulzbot.com/t/mintemp-e1-error-testing-rebuilt-toolhead/26712/1 "2024-05-30T18:59:22Z")

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Still rebuilding my SL toolhead. Had trouble with reseating the Molex pins for the heater element but think they are now repaired. When I try to preheat the hot end, getting immediate mintemp error. If I measure the resistance at the connector pins for heater and thermistor, what values should I find if they are OK? (both new)

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**Author:** ![McLeach](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/mcleach/32/11215_2.png) [@McLeach](https://forum.lulzbot.com/u/McLeach)\
**Post date:** [May 30, 2024, 7:29pm UTC](https://forum.lulzbot.com/t/mintemp-e1-error-testing-rebuilt-toolhead/26712/2 "2024-05-30T19:29:54Z")

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We actually have a guide on testing the heater cartridge and thermistor on our OHAI page linked below.

> **[OHAI: Open Hardware Assembly Instructions](https://ohai.lulzbot.com/project/testing-thermistor-and-heater-cartridge/tutorials/)**
>
> Open Hardware Assembly

The bottom will have rough values of what you are looking to see.

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**Author:** ![Wrathernaut](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/wrathernaut/32/13542_2.png) [@Wrathernaut](https://forum.lulzbot.com/u/Wrathernaut)\
**Post date:** [May 30, 2024, 8:12pm UTC](https://forum.lulzbot.com/t/mintemp-e1-error-testing-rebuilt-toolhead/26712/3 "2024-05-30T20:12:46Z")

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What does the screen show for your nozzle temp before trying to heat?

If it’s 0°/0°, the thermistor isn’t connected to the motherboard, or the thermistor has completely failed.

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**Author:** ![mhristau](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/mhristau/32/9696_2.png) [@mhristau](https://forum.lulzbot.com/u/mhristau)\
**Post date:** [May 30, 2024, 8:55pm UTC](https://forum.lulzbot.com/t/mintemp-e1-error-testing-rebuilt-toolhead/26712/4 "2024-05-30T20:55:26Z")

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Yep- 0/0° on nozzle. So, it should be some ambient temp value. Must have damaged the thermo somehow. It registers 128 ohms.