I have a fairly new A1 (not mini). It was working fine (about 90 hours print time). I added the AMS lite and it immediately wanted to do a firmware update (I assume for the AMS). The unit is on v01.04.00.00
I did a small test print with the AMS and it printed fine, The next morning, I went to do a print (from the Handy app) and after a minute or so of preparing things, I got a heatbed temp error. I did not see a way to continue, so I restarted the machine. It then printed fine the rest of the day.
The next day (today), I went to do another print and was trying to pay more attention to the display. I saw the bed temp rising and it was getting warm, but as I went to the other room to get something, the same error came up. Once again, I had to restart the machine and it was fine after that.
Has anyone had this happen? Any ideas what cause it (i.e. maybe not heating up fast enough)? When I watch things when it’s working, I notice the temp rises sort of slowly until it gets to about 60c, then it goes up to about 90c fairly quickly and then slowly comes back down to 65c where it stays. Not sure if that is normal or not because I never really paid attention to it before.
I have read that some heatbed temp errors say the circuit is open and in some cases even a restart will not clear it. Unfortunately, I don’t recall the exact wording of the error, only that it was temperature related and referred me to the wiki.
I was going to submit a support ticket today, but after filling out all of the info, it required a picture or video in order to continue. So I will have to wait until it happens again before I can do that. Just came here to ask if this is common, or if my A1 is having serious issues that will need a new heatbed or other components. .
Ok, here is some more data. The machine had totally cooled down and I started a print. As it was going through the procedure (bed leveling etc.) I watched the display. The temp was rising and got to 41C then started to drop, It got down to 31C then started to rise again. When it got to 34C, it errored out. The error was “Heatbed temperature malfunction” . After I closed that box, I saw the temp was rising again, but never got above 45C. But the temperature display was white at that point as if it was ok,
I then stopped the print and started all over. As I noted in the previous post, when it gets to about 64C, the temp jumps quickly to like 95C, then slowly comes back down to 65C when the printing is about to start. it is fine then on.
I do have a video and pictures, so I will send in a support ticket and see what happens. I have a feeling something is broken. I am going to try to do a full re-calibrate since I did not do that after the FW update for the AMS. Not sure if it;'s necessary, but can’t hurt at this point.
And what was the set point for the heat bed at that point? As it changes by build plate… i.e. Cool Plate defaults to 45C, textured plate to 65C, etc.
The sudden jump to 95C sounds wrong… maybe you have a broken lead to the sensor/faulty heat bed sensor… my A1 with 439 hours on the clock will very quickly warm up to 65c (textured build plate), sometimes overshoot by 1-2 degrees, and then literally just sit there at 65c.
I have always had the textured plate selected. However, after the error, I do not know what the software decided to do. All I know is the temp display turned from green to white as if it was in the proper range (which it was not). I assumed since it was still trying to do the print I had selected prior to the error, that would keep trying to get to 65C. After I hit stop and started all over, it worked fine (except for that temp jump).
Yes, I think something is wrong. However, this is repeatable. For example if I manually set the bed temperature to 65C from the control panel, it will go to 64C pretty much one degree at a time, then suddenly jump to 80C then 95C in like 2 seconds. That would appear to be like some faulty sensor or lead, but then it will slowly drop back down to 65C (like one degree at a time) and then stay there like it should. It only “jumps” on the way up, not on the way down, and always at the same spot. And since it’s repeatable every time, not sure what is going on (hardware or software). Prior to this error, I never paid any attention to the readings during the prep for printing so I don;t know if it always did that or not…
This all started right after I installed the AMS and it did a short firmware update. Coincidence or not??
Update: I took a video (link below) of what happens when I use the control panel to manually set the temp. The machine was “cold” from sitting all night. The bed started out at 23C. After about 90 seconds it had gotten to about 45C and then the temp starts to drop and the machine appears to reset the set temp to 0C. (took me a while to notice this) I assume this is where I would have gotten the error pop up during a print because perhaps it is taking too long.
I then reset the temp to 65C again and it starts to climb. When it gets to 61C, it starts to jump up again quickly to 103C before slowly dropping. when it gets to about 70C, it starts dropping faster to like 49C then starts going back up. So something is definitely wrong.
But here is the sort of strange part, once it gets back up to 65C, it then stays there just like it should. I would think a wire issue would cause it to be intermittent, especially when printing. However, I can see how a flaky sensor might “settle down” once it has been heated up
I tried a few other things. First I did a factory reset and re-calibration. No luck. Then I measured the heatbed senor. It was 107k ohms which did not seem to be too far out of spec. Took a picture of that and added it to my support ticket (since they may ask for that).
Next I downgraded the firmware and had a glimmer of hope because on the previous version, setting the bed temperature with the control panel is different than on the latest version. But that did not help either. I reapplied the latest firmware.
I think things are actually getting worse, because previously, once it got to 65C and stayed there for a bit, it was good to go. Now it wants to keep fluctuating over and under that by 10C or so. Looks like I will be out of commission for a while.
I think I may know what the issue is. I think the temp sensor in the bed is not making good physical contact with the bed. So when it looses physical contact, the temp of the sensor drops and the machine tries to heat the bed more (which is happening as I have monitored it with a temp gun). Then when it makes contact again, the temp shoots up to what it actually is. This cycle then repeats causing the wild fluctuations above and under the set temp…
I have sort of confirmed this by reaching my finger under the bed where the cable goes in, and if I push on the cable I can see the temp sensor start to work properly for a little while. But then after it sits for a bit, it starts to act up again.
I watched a youtube video of someone opening up the heat bed. But in order to do that, you have to muck with the spring loaded leveling which I don’t want to do at this point. Other than that, it looks pretty straight forward. Too bad they didn’t put a small removable cover over the spot where the sensor and thermal overload switch are. That would have made repair a lot easier.
Video link isn’t working for some reason, but, yes, good point… a broken wire would be intermittent, as the bed moves. But it sounds promising you’ve pinned it down to possibly being the sensor… hopefully support will help resolve this… might be a bit of a wait though due to Chinese New Year (on top of the long delays people have commented on).
Yes, and it would cause the reading to go off scale as it opened or shorted. I do think the sensor is working, just not making good contact with the bed all the time. Yep, frustrating to have to wait on support, especially when they will probably be backed up when they get back. .
Well, I am going to mark this thread “solved” because I was still within my return window, and I decided to go that route. A replacement is already on the way. I will probably get that before my support ticket is answered. let alone any parts sent.
Hopefully the replacement unit has no problems. Too many threads here about issues right out of the box.
Fantastic! To be honest, unless you want to be messing around with the heat bed and sensors, I think that is the best resolution. Not the sort of thing you want to have to be doing after so few hours on the clock. Fingers crossed round two goes better
