# Lulzbot Mini 1 won't connect **URL:** \ **Category:** General\ **Created:** [January 15, 2023, 7:56pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250 "2023-01-15T19:56:20Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![b-morgan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/b-morgan/32/11517_2.png) [@b-morgan](https://forum.lulzbot.com/u/b-morgan)\ **Post date:** [February 3, 2023, 2:24pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250/21 "2023-02-03T14:24:57Z")
I’d guess that this error is related to a thermistor or thermistor wiring issue. I believe at room temperature, the thermistor should have a resistance of approximately 100 ohms and, of course, the wiring between the tool head and the controller board needs to be intact. A little troubleshooting with a multimeter should confirm my suspicions. ---
**Author:** ![rabunnative](https://avatars.discourse-cdn.com/v4/letter/r/258eb7/32.png) [@rabunnative](https://forum.lulzbot.com/u/rabunnative)\ **Post date:** [February 3, 2023, 4:27pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250/22 "2023-02-03T16:27:50Z")
Thanks again. I’ll do some more probing and inspection this afternoon. **There is a thermistor on both the tool head and the print plate, correct?** Even if the printer never works, I have some students working with me as we troubleshoot various parts of the system and we are learning a lot in the process! ---
**Author:** ![b-morgan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/b-morgan/32/11517_2.png) [@b-morgan](https://forum.lulzbot.com/u/b-morgan)\ **Post date:** [February 3, 2023, 5:16pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250/23 "2023-02-03T17:16:59Z")
Yes, there is a thermistor on both the tool head and the print plate. You would have to check the [OHAI](https://ohai.lulzbot.com/) documentation to determine if they are the same type. However, the probability of a thermistor failure is much lower than the probability of a broken wire between the thermistor and the controller board. BTW, the [OHAI](https://ohai.lulzbot.com/) documentation for your Mini 1 (use the serial number to determine which model) should also contain pinouts for the tool head connector. You should also be able to find controller board diagrams as well. ---
**Author:** ![rabunnative](https://avatars.discourse-cdn.com/v4/letter/r/258eb7/32.png) [@rabunnative](https://forum.lulzbot.com/u/rabunnative)\ **Post date:** [February 3, 2023, 10:55pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250/24 "2023-02-03T22:55:13Z")
OK, I did a continuity check on the wires going from both the bed thermistor and the tool head thermistor to the board and everything checked out. I checked the resistance on the bed thermistor and it was 118. When I checked the tool head thermistor, I just got an OL reading on my Fluke Multimeter. It appears that I have a bad thermistor on the tool head. If someone agrees with this assessment, I will start looking for a replacement hotend. ---
**Author:** ![b-morgan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/b-morgan/32/11517_2.png) [@b-morgan](https://forum.lulzbot.com/u/b-morgan)\ **Post date:** [February 4, 2023, 3:12pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250/25 "2023-02-04T15:12:17Z")
I agree with your assessment but you shouldn’t need a replacement hotend, the thermistor can be replaced. If you feel like that is a task you don’t want to take on, I’d guess that you could send the tool head to [LulzBot](https://lulzbot.com/support/lulzbot-repair-service) or [IT-Works 3D](https://itworks3d.com/) and get it repaired for less than the cost of a new tool head (which is what I assume you meant when you said replacement hotend). ---
**Author:** ![rabunnative](https://avatars.discourse-cdn.com/v4/letter/r/258eb7/32.png) [@rabunnative](https://forum.lulzbot.com/u/rabunnative)\ **Post date:** [February 6, 2023, 2:31pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250/26 "2023-02-06T14:31:37Z")
As I was researching a possible repair, I came across this ([OHAI: Open Hardware Assembly Instructions](https://ohai.lulzbot.com/project/replacing-lulzbot-mini-hexagon-hot-end/maintenance-repairs/)) which seems to indicate that I can replace the hot end without replacing the entire tool head. Are you saying that there is a possibility of just buying the thermistor by itself without even having to buy a new hot end? If that is a possibility, I feel fairly confident that I could take on that repair myself. Let me know if you happen to have a link to the specific part that I would need. Thanks. ---
**Author:** ![b-morgan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.lulzbot.com/b-morgan/32/11517_2.png) [@b-morgan](https://forum.lulzbot.com/u/b-morgan)\ **Post date:** [February 6, 2023, 2:49pm UTC](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250/27 "2023-02-06T14:49:49Z")
You should be able to replace the thermistor. I believe it is an [EPCOS 100K](https://www.newegg.com/p/298-005B-00059?item=9SIA7ANE2M9979). Here is a decent set of [instructions](https://tamarintech.com/article/hexagon_std_assembly). You can also contact the support folks at the links in my previous post and ask them if they sell the thermistor or can verify that the part I posted is the correct one. [Previous page](https://forum.lulzbot.com/t/lulzbot-mini-1-wont-connect/25250.md?page=1)