With a 2.2kohm pull up and cold temperatures resulting in 208kohms of resistance, you're asking the ADC to accurately measure about 0.03 volts relative to the 3.3v rail.
3D printer thermistors/boards are designed for accuracy around 200C, (at this point, thermistor and pull-up are similar so there's loads of accuracy/resolution), they don't have much accuracy at low temperatures. I wouldn't sweat it.
@mitch Lots of places to shift electronics (ebay, craigslist, offerup marketplace), I'm in agreement about saving it from a landfill. But seems really disrespectful to come here to do it. Just my 2c.
@RodrigoRMaraujo said in Duet maestro - Diag led does not turn off:
I've been buying Duets on AliExpress since 2019
Just curious, since you’ve benefited so much from their work without buying genuine hardware, have you offered to contribute to the Duet development team?
Is that a genuine product? It sounds like a clone. Super bold to come onto the official Duet3D site, funded by purchases of official Duet3D hardware, to sell a cloned product.
You're effectively asking someone to do development work for you for free. You've gotten a fair bit of (free) help so far. If that's not enough, you could consider contacting Duet3D to set up paid development work.
Seems like another possibility is that the ribbon cable isn't fully seated, photos would be useful.
@remzirecep Yelling for help is not a path to a solution.
Posting the aforementioned photo is a path to a solution, as is posting the changes you've made to the code.
You're getting a reply from the lead firmware author. Maybe a little appreciation for that would be helpful too.
@PDBeal This is the first I've heard of these incompatibilities, lots and lots of these sold. Certainly not meaning to hide anything, and happy to publish any official incompatibilities on the product page. First, need to ascertain whether the incompatibility is firmware based or PCB based. What say you @T3P3Tony ?
PDBeal - I'll add that these PanelDue PCBs are EOL'ed, less than 10 remaining at Duet3D and only a few here. So hesitating to buy another probably means just not buying another, since they'll be OOS soon.
Just to close the loop on this, PanelDue PCB was received and tested fine. Did need to reflash the firmware as it arrived seemingly in an erased state, but no issues after flashing, see photo:
@opentoideas said in hotend Recomendations - looking at E3D Revo:
before I make a mistake is there a reason they don't do this kit?
Just low demand, no issues with it. But you could just pick a hotside kit and add a Revo Micro heatsink/duct/fan. https://e3d-online.com/search?q=revo+micro&options[prefix]=last
Your config.g file has a M552 S1, which tells the board to enable networking as a client, not an access point. Board's just doing what you're telling it to 
@Hlwanczyk Please post your config.g file, a photo or two showing your board's wiring, and the commands you used to set up the access point.
@new_to_me901 Thats a AP2127K chip and AP7361C chip, 3.3v regulator chips that provide that provide the 3.3v rail for the board. That regulator has overload and over temperature protection, so if you've blown it up I'd surmise you've somehow applied 5v or more to the 3.3v rail. Would bet there's more damage than just the regulator.
Is that board sitting on metal in the photos?
@FrankHowardNUSA Railcore Discord is the place to ask those questions, not enough people here familiar with Railcore. There are stock configs posted for Duet 3 on a Railcore. You'd want to use a 6HC (and a 1LC if you want a CAN-connected toolboard).