RE: Watchdog Reset on all prints, even self test
@lespickin
I have a nearly identical video from when I first set up my machine. That's the topic here: if the nozzle temperature is 15 or less, it will reset when you turn the heater on. You can avoid this problem by heating it up first with a hairdryer or even just holding your fingers on it for a minute or so. Once the display shows at least 16 you should be able to start it up without the crash.
The reason I think this is important to fix is because it's creating such a negative experience for people who run into it, as can be evidenced by your post. It doesn't matter that it's easy to work around, because most people will not know about the workaround when they get their new printer, put everything together, excitedly try to run the setup or their first print, and it's suddenly red screening.
Frankly, I'm very impressed by this machine. Once I got past the initial mintemp crashing, it has been producing excellent results. I brought my first Bench print into the office and my maker friends have much admired it. I think it's a great printer for the price, this is just a minor problem with an oversized impact that can probably be fixed with 10 lines of code.
RE: Watchdog Reset on all prints, even self test
Frankly, I'm very impressed by this machine. Once I got past the initial mintemp crashing, it has been producing excellent results. I brought my first Bench print into the office and my maker friends have much admired it. I think it's a great printer for the price, this is just a minor problem with an oversized impact that can probably be fixed with 10 lines of code.
I don't think this will be "fixed" and honestly I would not want it to be.
15 degrees has always been the min temp of all PR printers (except the early Mk1 days) and has been implemented as a safety feature.
The thermistors used in the hot end can be very inaccurate at lower temps. Overly high values (ie less than 15 degrees C) could easily indicate a faulty thermistor or cable and would result in the heater cartridge being turned on without being limited.
I don't know if you have seen the results that this can lead to. If not, just do a quick search on YT.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
RE: Watchdog Reset on all prints, even self test
@pjr
That would be very unfortunate, because it would mean the printer is not fit for purpose within its advertised specifications. I suppose rather than a thread full of speculation, I should reach out to Prusa support to get a definitive answer. As much as I like this machine, I'm not sure I'd want to keep it if this is a won't-fix scenario.
RE: Watchdog Reset on all prints, even self test
Please ignore my previous reply, it was unnecessarily combative but I waited too long to be allowed to delete it.
To repeat myself, there is a simple and safe way to deal with this: ignore temperature readings for 5 seconds after turning on the heater. This will easily get it out of MINTEMP range if the thermistor is not broken and it's merely cold. If it is broken, 5 seconds of heating is not enough to cause a fire.
There are solutions. It shouldn't be a rite of passage to have to learn how to work around this defect.
I jumped back in to help @lespickin, but I've gotten distracted and sucked back in to an argument again. I really need to stay out of these threads and focus on the positive.
RE: Watchdog Reset on all prints, even self test
@masto
Lol, it's not worth arguing about. It's a pain in the arse and it should never have happened along with the other issues people are having.
It's not the end of the World it's just a duff printer. You really shouldn't have to fix something or find workorounds for problems when it's new - that's what testing is about!
They have also agreed that I can send back the machines for a refund which is great and good customer service - which I've always had btw
RE: Watchdog Reset on all prints, even self test
My Mini worked fine on Day 1, on Day 2 I plugged in the USB Key, hit "print" and it thought about it for a moment then did the Watchdog Timer reset thing. The very simple solution for me was to select "Preheat [PLA]" (which sets the temp target to 215) then immediately (just seconds later) select Print which resets the temperature to 170 so it can do it's calibration routine. At this point everything ran fine.
It seems like the firmware (the latest as of 3/7/2020 - I think 4.4 or 4.04?) has some type of temp startup issue that manually selecting Preheat seems to fix, at least my two cents.
Besides this quirky issue very much lovin' the Mini.
RE: Watchdog Reset on all prints, even self test
Don't use a high temp heat gun to warm the nozzle. I melted the parts cooling fan doing that.