Update on the issue of noise on the temp sensor.
It still happens. Replaced the rambo with a new one. Replaced the thermistor. Bypassed the wiring of the thermistor with a new one.
It still happens…
Sooo. Lulzbot in their infinite wisdom run the hotend fans off the 5v instead of 24v. You know what a fan running on the same supply as the logic does?
Probably a stupid question but did you try re-tuning the PID for the hotend after replacing all that?
Yep, i did. I also got the oscilloscope out and measured everything. Thats what gave it away.