Hotend Won't Heat Up (I've Tried Everything in the Book)
Hi All,
I've been in FDM printing for 5 years now, and for the first time I'm stumped.
I recently changed my MK3S' hotend to a ceramic one, because if how good the performance was on another MK3S I had.
When I changed the hotend the first time, it heated up, I put in the nozzle, and it just crashed. I thought nothing of it, restarted the printer and it refused to heat up again, despite me measuring 24v at the hotend leads itself.
Thinking it was just a bad one I got another, installed with the same process, and same result. Refuses to heat up after that very first time when it actually did.
Same story, I can measure 24v at the leads no problem. The hotend spec is also 24v. Both old and new ceramic ones are over 500k ohms in resistance, so they are definitely kaput. But I have no idea why.
I've installed the newest firmware as well, and fuses are all okay (especially since I can actually measure some voltage at the leads). Thermister is perfectly fine as well.
Please share any advice you might have. I have really no idea what the problem is, and I'm at my wits end with this printer.
Thank you.
RE: Hotend Won't Heat Up (I've Tried Everything in the Book)
Are you sure that the ceramic heater was a 24 volt heater?
If it were a 12 volt / 40 watt heater, and you connected it to 24 volts, then the hot end would try to draw 160 watts. Which, if the heatbed is heating at the same time, is likely to overload the power supply which could crash the controller...
it's possible that 4 times the rated power dissipation could also cook the heater module...
did you measure the heater resistance before applying power to it?
that would give you a bit of an idea what rating the heater was originally.
as you say... 500Kohms is way too high a resistance.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: Hotend Won't Heat Up (I've Tried Everything in the Book)
Hi Joan,
Thank you for your reply.
You make a good point. To be perfectly honest, I am only going by my trust in the seller that it is indeed 24v.
This time (third time) I am going through a different seller again, and will make sure to check the resistance before I use it, and see how it goes.
Thank you.