Howdy All!

Over this weekend, I have been converting my CR-10 Mini from Bowden to Direct Drive and that involved taking a part the hot end to swap out the mounting backplate. Well after I was done putting things back together I have noticed that the hotend temp is no longer able to stabilize and I have no idea why. I will set the temp to 190 and it will get up there pretty fast (with a 40W heater) and yet it will overshoot by 5 or so degrees and settle into a consistent rhythm of going up to 193 and dropping down to 187 and up and down like a yo-yo. I have left it for a good 15 mins and it still does not stabilize or move out of its up and down rhythm. Thinking it was maybe I did not seat the thermistor or heating cartridge in correctly I took both out of the block and carefully reseated them. It made no difference.

So curious - I put a multimeter on a V- and V at the back of my power supply across the wires that go to the mainboard and observed a consistent 12.04V being output. I then put my multimeter across the input screw terminals on the mainboard and noticed a voltage fluctuation between 11.98 and 12.04 volts up and down roughly to the same rhythm as the hotend temp fluctuations. The mainboard is a BTT SKR Mini E3 V2.0 which I swapped out from the Creality v1.1.4 8 bit stock CR-10 mainboard a few months back.

I also did several pid tunes and reconcompiled the firmware thus and it's made no difference. I am running my own custom configured version of Marlin 2.1.2.4. I always ran each cycle 8 times to get a more accurate value.

I recorded a quick video of the issue and what I have observed:

https://photos.app.goo.gl/t1HQdt35WiHen9iv7

Any idea what this could be or what I could do to troubleshoot it?

Thanks so much in advance!

======== UPDATE ========

Well turns out my issue was user error. BTT Support suggested I do a EEPROM reset and so I did that and then did a PID tune and save and retested and now everything is fine. Temps are holding steady with no fluctuations. I learned something new today!

So if anyone stumbles across this and has the same issue I have try doing a EEPROM reset and then PID tune and then check again before you go through the hassle of changing out your board.