MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
Topic explains issue. Reaches temp fine after a cold boot, but about 15 mins into the print it will start to rapidly lose temperature. At first I thought it was a part fan issue, as my quicker prints were getting further along before failing, but I've had prints fail on the first layer before the part fan turns on, always about 15 minutes into the print. I've tried multiple slicers (cura and slic3r prusa edition) and also have flashed to the newest firmware. I've barely used this printer (first bought in january preassembled, only printed about 20 things on it, all under 8 hrs) I'm not sure what is going wrong. I've had kit printers before but I've never had an issue where heating is intermittent, it's normally a binary issue (either it works or doesn't) so I'm at a loss what to troubleshoot here.
RE: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
Don't know why I can't edit my post anymore, Just wanted to add that I've been printing over SD. I found another post on here with someone having the same exact issue who also says they tried a new heater cartridge, which was my next guess to what the issue is, the only thing that was making me think that's not it is the consistency with powercycling solving the problem. The only difference between our issues is he gets a whole hour before the print fails.
RE: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
Hi Swizzler,
there may be an interaction between the S3D session and the printer,
Could you try the print off an SD card?
if , for instance the USB session resets, then the printer will loose the connection and the current print will fail!.
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: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
I have only been printing off SD cards so far. thank you for the reply.
RE: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
If you have a voltmeter, it would be useful to connect a couple of wires to the einsy where the nozzle heater connects and connect them to the voltmeter. Watch the voltage before/after the change.
If the voltage is the same, there is something going on in your heater cartridge. If the voltage drops when you lose temp, I’d replace the thermistor. If you have the same problem with a new thermistor, there is something funky with the board/firmware.
I don’t think this is likely to be the issue, but it wouldn’t hurt to flash the latest firmware and do a PID calibration on your nozzle before any of the above and see if that helps.
RE: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
How old is the printer? How many print days in Status?
A bad heater fits the failure description. Could also be a faulty thermistor that opens up, the software detects the break and shuts off the heater. And before you notice the temp display went to zero the thermistor self heals and all you see is a cooling hot end.
As for flashing new firmware to solve a hardware problem ... well, you risk adding to your troubles because now you'll need to do a factory reset and full recalibration, which you probably can't complete because of the hardware problems, so now you have two issues to solve.
RE: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
If you have a voltmeter, it would be useful to connect a couple of wires to the einsy where the nozzle heater connects and connect them to the voltmeter. Watch the voltage before/after the change.
If the voltage is the same, there is something going on in your heater cartridge. If the voltage drops when you lose temp, I’d replace the thermistor. If you have the same problem with a new thermistor, there is something funky with the board/firmware.
I don’t think this is likely to be the issue, but it wouldn’t hurt to flash the latest firmware and do a PID calibration on your nozzle before any of the above and see if that helps.
Will do and will report back sometime today. I have already tried flashing to the latest firmware with no success.
Posted by: tim-m30
How old is the printer? How many print days in Status?
Only about 6 months, Got it in February. If it is a bad thermistor/heater, should I contact Prusa, would they send out a replacement part under warranty?
RE: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
Update: Did the diagnostic paul suggested, voltage drops on the heater right before thermal runaway indicating bad thermistor along with others on the forum with very similar issues also noting bad thermistor. currently trying to contact support about a replacement.
RE: MK3S Hotend fails loses temp rapidly ~15mins into print, powercycle fixes for another 15 mins.
Go to EShop and open a chat window.
They should step you through any additional troubleshooting necessary for a Prusa MK3S.
If it is the power supply - I don't actually know what our warrantee is. Support is really good about replacing anything under warrantee.
Thermistors and heaters are cheap enough to just buy a couple of spares. They are pretty much consumables.