I have a headless PiZero with a wifi dongle using a RPI PSU (and it's running Domoticz).
It boots fine and is all OK until I boot it with my long (20m?) wire of DS18B20s connected. With that plugged in, it comes up, I can log in, but within, say, 30 seconds, wifi connection is gone (confirmed by the router).
One time when I booted it with the temp sensors plugged in, it said "Failed to get D-Bus connection" but I haven't seen that since.
It works OK with a short wire with one DS18B20 plugged in. Also, when booting w/o the long wire, Domoticz claimed to have seen one of the sensors on the long wire which suggests that the wire is all OK (I did buzz it out for shorts etc. before I used it).
If no one knows of a good reason why this might be failing I will have to disconnect my wire at various points, but it's all behind kitchen cabinets etc. so that's a nightmare, so if anyone has any experience of this, or good ideas, please let me know!! :o)