Prusa MK3 resets when heating  

Re: Prusa MK3 resets when heating

I had this same problem and the fix was to replace the OEM PSU with a Meanwell NES-350-24 PSU. This one has more wattage and a cooling fan.
Good luck with this situation.

Re: Prusa MK3 resets when heating

An update:

I did some more testing and going through settings.

When I preheat the bed it works fine and heats up.

When I preheat the hot end it resets.

I'm in America if that helps; but I haven't heard that I'd have to buy my own powersupply while I was still considering buying this.

Is supplying my own PSU really a thing?

Re: Prusa MK3 resets when heating

I’d contact support regarding this. Provide a video to move things faster. I’m in Oregon and been using stock PSU with no issues. It does the classic clicking noise but things work fine. If problem is psu or board or whatever part is faulty then support will send you a replacement

Re: Prusa MK3 resets when heating

Definitely contact support. You have a fault. Your printer should not reset while heating. You may need a replacement Einsy board for instance. You do not have to replace your PSU to have a working printer, that is simply a choice some users have made.

Make a short video of the issue and send it to support, be prepared to wait a few days as they are insanely busy but they will help you out.

Good luck!

Re: Prusa MK3 resets when heating

I appreciate the feedback from everyone. I'm going to reach out to support. I took a video of me trying to heat the nozzle.

I also accidently showed that if I put the nozzle below it's current room temperature it doesn't reset (I put it to 16 C and it didn't do anything) but the moment you attempt to heat it the device reboots. (I bumped it up to 40 C)

I think that rules out the thermister as well, leaving just the hot end the PSU.

If anyone has any other ideas let me know, but I'm going to persue support first.

Re: Prusa MK3 resets when heating

I appreciate the feedback from everyone. I'm going to reach out to support. I took a video of me trying to heat the nozzle.

I also accidently showed that if I put the nozzle below it's current room temperature it doesn't reset (I put it to 16 C and it didn't do anything) but the moment you attempt to heat it the device reboots. (I bumped it up to 40 C)

I think that rules out the thermister as well, leaving just the hot end the PSU.

If anyone has any other ideas let me know, but I'm going to persue support first.

i would bet it is shorted. you may have the wires backwards on the einsy or something similar.

Re: Prusa MK3 resets when heating

I appreciate the feedback from everyone. I'm going to reach out to support. I took a video of me trying to heat the nozzle.

I also accidently showed that if I put the nozzle below it's current room temperature it doesn't reset (I put it to 16 C and it didn't do anything) but the moment you attempt to heat it the device reboots. (I bumped it up to 40 C)

I think that rules out the thermister as well, leaving just the hot end the PSU.

If anyone has any other ideas let me know, but I'm going to persue support first.

i would bet it is shorted. you may have the wires backwards on the einsy or something similar.

I thought that when it happened the first time so I checked the connections and they seemed to be fine. I removed every cable from the board anyways and put them back on. Everything checks out fine. The wires are all undamaged and the connections match up to the assembly guide.

I submitted a support ticket and gave the link to this forum post as well, hoping that the additional information in here will help them to troubleshoot.

Re: Prusa MK3 resets when heating

Update: Support told me that the thermistor heat cartridge is likely the cause. They said it likely shorted out and are sending me a replacement. Since it worked once, I'm guessing it shorted out after that.

I'll update again if this fixes the problem.

Re: Prusa MK3 resets when heating

Final update:
Support sent me a new heater cartridge (and I ordered a few spare to have on hand) and it fixed the issue!

When I removed the old heater cartridge I noticed that the two metal wires that connect to the cartridge didn't have the wire wrap far enough and it was causing a short.

Re: Prusa MK3 resets when heating

Good that you solved it and found real root cause. :ugeek:

RE: Prusa MK3 resets when heating

@michael-b105

Hi,

Could you tell me exactly what the heater cartridge is? My prusa is out of warranty, and I'm having the same issue. Something went wrong with unscrewing the nozzle, there was a spark, and now my printer resets whenever the nozzle tries to heat up during initialization or diags. I think I need to order a heater cartridge. Do you mean the rectangular medal block that the nozzle screws into?

Thanks

RE: Prusa MK3 resets when heating

Hi,

Could you tell me exactly what the heater cartridge is? My prusa is out of warranty, and I'm having the same issue. Something went wrong with unscrewing the nozzle, there was a spark, and now my printer resets whenever the nozzle tries to heat up during initialization or diags. I think I need to order a heater cartridge. Do you mean the rectangular medal block that the nozzle screws into?

Thanks

This is exactly what happened with mine. What exactly did you need to fix it? Any advice is greatly appreciated

RE: Prusa MK3 resets when heating

mk3 series have 24 volt 40watt heaters

regards Joan

RE: Prusa MK3 resets when heating

I had this issue before, it's cause by the 90 degree bed wiring, the 3d printed part it is too tall and the extruder temp sensor wires hit against it.

RE: Prusa MK3 resets when heating

Hi, I just encountered this issue after I disturbed things when removing the nozzle.  Printer would reset as soon as I commanded nozzle heat.  Turns out the heater wires were shorted out.  I took out heater and was able to carefully push them apart with a small pick, which eliminated the short and fixed my problem.  Hope this is helpful for others.