<p>In my case, I had a bad resistor on my board. R41 had only 2.2 k&Omega; instead of 4.7. I replaced it and everything works now.</p>

CC BY-SA 4.0
2018-07-16T20:59:57.457Z
Just out of interest, how did you know that the value of R41 was incorrect, and what the correct value should be? Did you deduce it from looking at a schematic, or comparing like components or by calculation? Or was it just a faulty resistor, that was the incorrect resistance when measured with a DMM? Was the incorrect part caused by a manufacturing or design error?
Greenonline
CC BY-SA 4.0
2018-07-19T12:02:25.767Z
I measured it with Ohmmeter and compared the result against value written on it. I really don't know how resistor may become 'bad'. Shortening maybe?
honza-kasik
CC BY-SA 4.0
2018-07-19T12:07:22.113Z
It could have been badly soldered and over heated when the board was made; damaged in the fabrication process of the resistor itself, or; just got old? :-) **Note** that care should be taken when measuring components when on the board, rather than in isolation, as other components in parallel can change the actual reading.
Greenonline
CC BY-SA 4.0
2017-09-09T14:34:53.580Z
2018-07-16T07:34:43.243Z
2018-07-16T07:34:43.243Z
honza-kasik
<p>I've recently purchased Anet A8. First print went well, but now, the hot end temperature stays at ~230&nbsp;°C. When I touch it, it is still cold. I tried the thermistor, and it correctly changes resistance when I blow on it (from 100&nbsp;k&Omega; to ~70&nbsp;k&Omega;). The voltage in connector is about 300&nbsp;mV. </p>

<p>Does anybody know what could be wrong?</p>

CC BY-SA 4.0
2018-07-16T21:55:34.547Z
Apologies for the previously botched edit. Poor eyesight :-)
Greenonline
CC BY-SA 3.0
2017-09-08T11:05:34.390Z
Have you tried swapping the bed and extruder thermistors at the board?
tjb1
CC BY-SA 3.0
2017-09-09T14:35:27.107Z
I tried it. I fixed the problem, see my answer.
honza-kasik
<printer-building><hotend><anet-a8>
Anet A8 - hot end temperature still same
honza-kasik
# Anet A8 - hot end temperature still same

(Asked by: username_0 on 2017-09-07)

I've recently purchased Anet A8. First print went well, but now, the hot end temperature stays at ~230 °C. When I touch it, it is still cold. I tried the thermistor, and it correctly changes resistance when I blow on it (from 100 kΩ to ~70 kΩ). The voltage in connector is about 300 mV.

Does anybody know what could be wrong?

**Tags:** printer-building, hotend, anet-a8

> **Comments:**
> **username_2**: Have you tried swapping the bed and extruder thermistors at the board?  
> **username_0**: I tried it. I fixed the problem, see my answer.  
> **username_1**: Apologies for the previously botched edit. Poor eyesight :-)  

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## 1 answers

### Answer by username_0 on 2017-09-09. Score: 2 | Accepted answer

In my case, I had a bad resistor on my board. R41 had only 2.2 kΩ instead of 4.7. I replaced it and everything works now.

> **Comments:**
> **username_1**: Just out of interest, how did you know that the value of R41 was incorrect, and what the correct value should be? Did you deduce it from looking at a schematic, or comparing like components or by calculation? Or was it just a faulty resistor, that was the incorrect resistance when measured with a DMM? Was the incorrect part caused by a manufacturing or design error?  
> **username_0**: I measured it with Ohmmeter and compared the result against value written on it. I really don't know how resistor may become 'bad'. Shortening maybe?  
> **username_1**: It could have been badly soldered and over heated when the board was made; damaged in the fabrication process of the resistor itself, or; just got old? :-) **Note** that care should be taken when measuring components when on the board, rather than in isolation, as other components in parallel can change the actual reading.  

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