Printer quits due to thermal anomaly

[WobblyHand]

Was trying out some weird idea that I had to print and my Prusa i3 MK3S+ decided it had enough. It would loudly beep and then displayed Thermal Anomaly and paused the print. Prior to that it beeped a lot, but the temperature wasn't very far off, maybe 1C. After running self test and passing, and thermal management calibration, and PID calibration, all of which passed, I contacted Prusa for some help. While looking carefully at the hot end, I noticed that the thermistor wire was pinched or stuck. I did measure the thermistor resistance after it cooled down and it was around 110K ohms, which might be ok. Put everything back together and tried a small print from the SD card. (Normally I use Octoprint.) After only a few minutes, the printer beeped a lot and the printer did the Thermal Anomaly Pause again, pretty much the same behavior as when I tried to print a more complicated design from Octoprint. The pauses are not recoverable since they die within a minute or two of continuing. Certainly has been frustrating.

I've ordered a new thermistor, but I don't know if this will fix it. Hope it will though.

Anyone else run into this kind of thing? Seems weird it would show up more than a year after I built it.

 

[pdentrem]

Similar problem, Coworker had the cooling fan on the head fail. Turning but not fast enough.

 

[WobblyHand]

Similar problem, Coworker had the cooling fan on the head fail. Turning but not fast enough.

Strangely enough, I opened up the Einsy box and checked all the connectors this morning and found that the hot end fan connector wasn't latched into the mating connector on the board. It was loose, but working. The fan works better now - but I still get these anomalies..

 

[Ken226]

Was trying out some weird idea that I had to print and my Prusa i3 MK3S+ decided it had enough. It would loudly beep and then displayed Thermal Anomaly and paused the print. Prior to that it beeped a lot, but the temperature wasn't very far off, maybe 1C. After running self test and passing, and thermal management calibration, and PID calibration, all of which passed, I contacted Prusa for some help. While looking carefully at the hot end, I noticed that the thermistor wire was pinched or stuck. I did measure the thermistor resistance after it cooled down and it was around 110K ohms, which might be ok. Put everything back together and tried a small print from the SD card. (Normally I use Octoprint.) After only a few minutes, the printer beeped a lot and the printer did the Thermal Anomaly Pause again, pretty much the same behavior as when I tried to print a more complicated design from Octoprint. The pauses are not recoverable since they die within a minute or two of continuing. Certainly has been frustrating.

I've ordered a new thermistor, but I don't know if this will fix it. Hope it will though.

Anyone else run into this kind of thing? Seems weird it would show up more than a year after I built it.

With a pinched thermistor wire and measuring 110k ohms, my guess is the thermistor is bad. That seems the most likely suspect.

They are cheap. About 13$ for a pack of 3 on Amazon. Keep a few spares on-hand, just in case.

 

[WobblyHand]

Supposedly it should measure 100K at room temperature. I'm suspicious about the ones on Amazon, they don't look OEM, the cartridge end looks like a little bulb which may not have correct thermal contact to the hot end. Can't even tell if they are the correct diameter. They are cheap in general, so I did order one - but not from Amazon.

I have received quite a few counterfeit items from Amazon. Most of them I got my money back. The worst item was counterfeit water filters for my refrigerator, they leaked like a sieve, spraying water all over me. Bought the same item from an appliance store, it worked fine. Was one of the nicest looking counterfeit filters, you really could hardly tell it was fake, even the box it was in looked nearly identical, but there were tiny differences. Of course, the biggest difference was the counterfeits didn't seal at all. Got a full refund on those fake filters.

Amazon sold me a fake CPAP mask - that was fun. I reported that one too, and got a refund. Crappy seller pleaded ignorance, counterfeit medical goods, that takes the cake. Mask was packaged in a plain small bag. Real masks are in large bags, with all kinds of marking on them, part number, manufacturer name, country of origin, bar codes, etc. Not real impressed with Amazon, although I still buy from them on rare occasions.

 

[Ken226]

Supposedly it should measure 100K at room temperature. I'm suspicious about the ones on Amazon, they don't look OEM, the cartridge end looks like a little bulb which may not have correct thermal contact to the hot end. Can't even tell if they are the correct diameter. They are cheap in general, so I did order one - but not from Amazon.

I have received quite a few counterfeit items from Amazon. Most of them I got my money back. The worst item was counterfeit water filters for my refrigerator, they leaked like a sieve, spraying water all over me. Bought the same item from an appliance store, it worked fine. Was one of the nicest looking counterfeit filters, you really could hardly tell it was fake, even the box it was in looked nearly identical, but there were tiny differences. Of course, the biggest difference was the counterfeits didn't seal at all. Got a full refund on those fake filters.

Amazon sold me a fake CPAP mask - that was fun. I reported that one too, and got a refund. Crappy seller pleaded ignorance, counterfeit medical goods, that takes the cake. Mask was packaged in a plain small bag. Real masks are in large bags, with all kinds of marking on them, part number, manufacturer name, country of origin, bar codes, etc. Not real impressed with Amazon, although I still buy from them on rare occasions.

My Voron is home built, so theres no such thing as OEM, just a whole bunch of different brands. I'm using a Flysetc (spelling?). I bought a pack of 5, about a year ago for 12$, and I just swapped in the 2nd one a couple weeks ago. I didn't replace it because the thermistor went out, but because i broke the connector off while trying to unplug that tiny plug with my fat fingers.

Just a sec, ill go measure the resistance across one of my brand new ones and see what the resistance is.

 

[Ken226]

I taped the thermister to a block of 6061 aluminum that i measured with my laser thermometer @ 68f. I got 101k ohms.

 

[WobblyHand]

My point is only that I wanted to ensure the part I bought would fit my printer. I could make the cheapo part fit, but at this point I want a full OEM equivalent, even if it's $10. It may seem odd to you, but I dislike working on this particular printer. The design is not elegant, like a Voron, it's awkward and unpleasant to work on. So I just want the part to drop in place with no extra work.

 

[Ken226]

My point is only that I wanted to ensure the part I bought would fit my printer. I could make the cheapo part fit, but at this point I want a full OEM equivalent, even if it's $10. It may seem odd to you, but I dislike working on this particular printer. The design is not elegant, like a Voron, it's awkward and unpleasant to work on. So I just want the part to drop in place with no extra work.

Not odd to me at all. I stay OEM when I can, It's definitely the safe bet. My Flashforge Creator Pro gets OEM replacement parts. I'd probably buy OEM parts for my Voron if there were any such thing. I've had good luck with quality so far on Flysetc stuff, and the build plates i get from West3D.

 

[WobblyHand]

I've actually tried a Flysetc part for something else, and it didn't work as promised. Wrote that experience off as a learning experience. Was trying to use it as a wireless SD card. Fortunately it wasn't much money, but it did open my eyes.