# Node-red and ds18b20 disconnecting sensors, cause? Unplug power, then all ok again

**URL:** <https://discourse.nodered.org/t/node-red-and-ds18b20-disconnecting-sensors-cause-unplug-power-then-all-ok-again/8372>\
**Category:** General\
**Created:** [25 February 2019 14:29 UTC](https://discourse.nodered.org/t/node-red-and-ds18b20-disconnecting-sensors-cause-unplug-power-then-all-ok-again/8372 "2019-02-25T14:29:26Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ole88](https://avatars.discourse-cdn.com/v4/letter/o/977dab/32.png) [@ole88](https://discourse.nodered.org/u/ole88)\
**Post date:** [25 February 2019 14:29 UTC](https://discourse.nodered.org/t/node-red-and-ds18b20-disconnecting-sensors-cause-unplug-power-then-all-ok-again/8372/1 "2019-02-25T14:29:26Z")

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Hi.

I have 13 ds18b20-sensors connected to my Raspberry PI. 3 of the sensors stop working at various times, but often after 1 day, or 1 1/2 day. My other 10 works 24/7. It's the same sensors every time that stops and show the value zero.

A reboot does not fix the problem, but if I pull out the power cable and plug back in, it works fine. I reinstalled rabian and tried another raspberry, no luck.

Any suggestions to the cause?

My wires are connected all together in 3 points, positive 3v, ground, and signal. And a 4.7k resistor.

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**Author:** ![hotNipi](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/hotnipi/32/383_2.png) [@hotNipi](https://discourse.nodered.org/u/hotNipi)\
**Post date:** [25 February 2019 15:06 UTC](https://discourse.nodered.org/t/node-red-and-ds18b20-disconnecting-sensors-cause-unplug-power-then-all-ok-again/8372/2 "2019-02-25T15:06:22Z")

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Common reasons which are hard to detect

1. bad connection on IO pins
2. low/unstable voltage
3. faulty sensor

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**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [25 February 2019 16:15 UTC](https://discourse.nodered.org/t/node-red-and-ds18b20-disconnecting-sensors-cause-unplug-power-then-all-ok-again/8372/3 "2019-02-25T16:15:22Z")

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maybe some of this is useful - [https://lb.raspberrypi.org/forums/viewtopic.php?t=167896](https://lb.raspberrypi.org/forums/viewtopic.php?t=167896)