Printer began smoking then max temp exceeded alarm went off
I have a prusa MK3S+ (assembled by Prusa in September) and an Prusa enclosure (assembled by myself in January) and on Sunday this week, after a successful 1 hour print with some clear PETG I performed the filament unload. After putting away the filament, with the printer still up to temp (nozzle 230°C), I noticed smoke accumulating in the enclosure. I looked carefully and saw some smoke was coming from the print nozzle. There was black goop (I'm guessing filament from earlier) on the nozzle. I put the printer into the cooldown mode then watched. The nozzle temp weirdly jumped back and forth between 215 and 230 for a few seconds before suddenly reading over 410°C and the alarm sounding with the MAX TEMP error on the LCD. At that point I cut the power to the printer.
I haven't tried turning the heater on since. It seems to function normally when not heating so far with the nozzle / bed reading at room temperature (22°C). I don't see anything obviously wrong from the outside. Does anyone have advice on what I should do?
RE: Printer began smoking then max temp exceeded alarm went off
Update: I just did a self test and it finished with "All correct" / "Self test OK."
RE: Printer began smoking then max temp exceeded alarm went off
I would report this to Prusa support. Login to your Prusa eshop account and look for the chat button on the lower right of the page. If you don’t see it, you may have to temporarily disable any ad blockers. Good luck.
Cheers
RE: Printer began smoking then max temp exceeded alarm went off
This. New printer under warranty. No need to get help from randos on the internet, get on the chat with Prusa so they can get you (free) replacement parts if needed.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Printer began smoking then max temp exceeded alarm went off
Thank you! I will contact support
RE: Printer began smoking then max temp exceeded alarm went off
Just in case someone finds this in the future, I contacted support and they had me update the firmware to make use of the enhanced thermal anomaly detection in firmware version 3.12.x. The firmware prevented it from smoking but it would still fail with 'PAUSED THERMAL ERROR' on the LCD and failures got progressively frequent. After contacting support again, and sending a video of the issue, they sent out a new thermsistor. Installation took some care but wasn't too difficult and the printer has been problem free ever since.
Thanks