Load Cell & Filement Sensor Errors  

RE:

Does it tell you the loadcell or the FS was not initiated?

Did you try the filament senzor calibration? What happens after calibration?

The disconnected massage appears when you do not have connected the FS to the loveboard or the filament senzor cable is broken.

RE:

Yes, I did. The problem remains the same. The calibration is also retained after powering it off.
But I need to disconnect the nextruder cable and reconnect in order to be able to print or even calibrate.

The issue is consistently reproducible. On the firmware that was originally installed (4.7.2) and also on the current RC (5.0.0-RC).

It tells what I wrote in the first post.

Filament sensor: disconnected /0
Loadcell Value: Not initialized

Until i reconnect the cable.

The disconnected massage appears when you do not have connected the FS to the loveboard or the filament senzor cable is broken.

That is the weird thing. The cable is connected and worked without wiggling during whole prints.
The cable looks good and I also measured every crimped connection to ensure there are no high resistances on the contacts.

RE:

The cable is connected and worked without wiggling during whole prints.

Time to edit was over. What I meant: The cable is connected and the printer works like a charm during whole prints.
Wiggling does not cause problems.

TL;DR
Print done. Power off. Come back later. Turn back on. Sensors dead. Reconnect the Nextuder cable. Sensors fine again. Every time. Reproducible.

RE: Load Cell & Filement Sensor Errors

@sirprintalot

can you share a video shot? Do you really disconnect the main loveboard (nextruder) cable leading to the MK4 main alectronics box?

The main board communicates with the loveboard via communication protocol, which at the initiation starts to connect to the loveboard

RE: Load Cell & Filement Sensor Errors

Yes, I really disconnect the cable that connects the loveboard to the xBuddy board. After reconnecting the two sensors work again flawlessly.

I also can eliminate a defect on the loveboard, because I had a second one laying around that I used to check if the shipped one is "broken".

RE: Load Cell & Filement Sensor Errors

Do you unplug/plug the cable when the printer is on? Or do you switch off the printer first?

I have the same issue as you have described. It seems that loadcell and filament sensors SOMETIMES restore itself, but only after actions like: printer reset, test/calibration attempt. When this happens the print runs without problems.

RE: Load Cell & Filement Sensor Errors

This problem occurs the same as mine, i.e. when the sensors work, the printer works, but just turn the printer off and on again and the sensors are dead again.

 Only resetting or turning the printer on and off helps.

After repeatedly checking when exactly the printer receives and when it does not receive the signal from the Loadcell and Filament sensor, I came to the following conclusions.

Printer off -  on ( lack of signal! ) Loadcell Value: Not initialized Filament sensor: disconnected /0

It is not possible to perform a self-test, Loadcell test, etc.

This happens every time the printer is turned off and turned on again (no signal from the sensors)

The situation changes when, after turning on the printer, the first thing I do is move the Z axis using the knob in manual mode, just move a little in the Z axis, then immediately turn the printer off and on, or press the reset button, then after restarting the sensors - the sensors work again, and therefore everything starts working until the next time the printer is turned off.

Has anyone solved the Thebes problem?

RE: Load Cell & Filement Sensor Errors

Posted by: @janrija71

Do you unplug/plug the cable when the printer is on? Or do you switch off the printer first?

I unplug the cable while switched on. Plug it back in and everything works like a charm again.

After some back and forth with the customer support via mail and chat they're sending me a new xBuddy and loveboard. I'll keep you updated if the problem still persists after changing components.

RE: Load Cell & Filement Sensor Errors

Here is an update from my side. I have communicated this issue with the support and they asked me to remove the LoveBoard and wiring harness between the Nextruder and Buddy board and send it to them - they will send the replacement. I disassembled it and did a careful visual check of LoveBoard - no signs of damage, bad soldering, or cold junction have been found. The board looked perfect. Then I measured the cable harness. Both sides of the connector are connected 1:1 so it was easy to measure, but again no signs of bad contact. I'm a little worried that their proposed solution won't solve my problem 🙁

RE: Load Cell & Filement Sensor Errors

Hi guys, I'd also like to have my say. First of all, I am glad that I am not alone with this problem. Even before I found this thread today, the support sent me a new heat sink. After that was a flop. They sent me a new LoveBoard and xBuddy. I received both today. With full hope that one of these parts would solve the problem, I was unfortunately disappointed. Neither replacing the LoveBoard nor the XBuddy board did anything. Now I thought I had to look for it again and found this thread.

I also find that when I switch on the printer, the setup wizard starts. Of course, after the fan test, a load cell error occurs, then my extruder starts up and my printer restarts. The error message is displayed.

Now I have skipped the wizard to check what is going on with the sensors. As with you: load cell "Not initialized" and filament sensor "disconnected /0". I disconnected the extruder cable from the xBuddy and connected it. Lo and behold, the load cell and filament sensor work. I was able to do a few tests. With the Y test I got an error and Z was not carried out at all. Anyway... I first tried whether Auto Home works. Everything works. I did some manual tests so that I can start printing something. It looks like everything is going very well. Well, then I switch off the printer and as you know. Everything has to be done from the beginning. The setup wizard starts from the beginning.

After waiting so long for the pre-order and two weeks waiting for all the parts, I am "first of all" happy that I could print something.

I'll now try to contact support again and see what solution we can find now. Maybe the extruder cable is actually defective, broken or defectively produced.

I'll let you know when I have more info.

RE: Load Cell & Filement Sensor Errors

Experiencing the same issues..

Glad I found others. I'm reaching out to support as well and will update on any findings on my end as well.

RE: Load Cell & Filement Sensor Errors

I just completed my MK4 kit construction and encountered the LoadCell not intializing error ... consistently.   I have contacted support but they haven't offered a solution.    I am going to try some of the steps posted in this tread and I'll report back on what I find.    Glad I found this thread, but dread the issue!   

RE: Load Cell & Filement Sensor Errors

Well, all your hints at possible workarounds worked!    Tried the z-axis move but that didn't work.   However, the unplug of the LOVE board at the BUDDY board connector while powered up DID work.   I now have completed first deployment and am printing my first test print.  

RE: Load Cell & Filement Sensor Errors

I also have this problem on my recently assembled MK4. Today I reached the stage where I was unable to to get the load cell and and filament sensor to work even after repeatedly using the reset trick after moving the axes etc. which had been working for me.

I then tried removing the USB stick, powering off, waiting a few seconds then powering on again. Once the printer was up I checked the status and both sensors were at last OK again. I then plugged the USB stick back in and I had a functional printer.

I have only used this trick once so far, so its apparent success may have been a fluke. I will see what happens later today when I am next awake and post an update.

The reset trick has been becoming progressively more difficult to get to work over the last day or so. One thing that has been changing over the period is the number of gcode files on the stick.

RE: Load Cell & Filement Sensor Errors

My previous post about removing the USB stick then powering on was a red herring. It did not work this morning.

Today's "successful" approach was to leave the printer on, pressing reset occasionally at something like 1, 5, 8 minutes after the initial power up. Following each reset I left the printer displaying the sensor readings. I did not touch anything else. Tomorrow I will leave the printer on for 10 minutes before my first attempt at pressing reset.

For info, I am currently running firmware 5.0.0-RC. I also had the problem with version 4.7.2.

RE: Load Cell & Filement Sensor Errors

I believe that I actually have a consistent solution that works for my MK4 with 5.0.0-RC (I have not tried it with 4.7.2 as testing is time consuming).

Throughout today I have been leaving the MK4 turned off for periods of the order of 1.5 to 3 hours. When I turned the printer on and displayed the sensor values, the load cell and filament sensors were always non functional. When I reset the printer about 10 minutes after power up then, at least for today, it has always come back fully functional. During the interval before the reset at 10 minutes, apart from displaying the sensors, I did not do anything else to the printer. 

Thus I have had a fully functional printer on 4 consecutive occasions following a reset about 10 minutes after power up. On two of the test runs I also did a reset about 30 seconds to 1 minute after power up. In these cases the load cell and filament sensors remained non functional as expected until the second reset at about 10 minutes.

It is necessary to leave the printer turned off for some time as, if it has been in use for a while, it can come back functional after a short power of period. I will next be letting Prusa support know these details.

I will run at least one more power up test tomorrow morning (UK time).

If this is a temperature dependent problem then your local environment may influence how long you should wait before pressing reset. Today my room temperature was between 22 and 24 C and my main board sensor had risen to about 34 to 34.8 C at 10 minutes.

I chose 10 minutes as it is a bit longer than the single 8 minute interval that I mentioned my earlier post today and I wanted to try to avoid getting any expected failures.

RE: Load Cell & Filement Sensor Errors

The reset 10 minutes after power up is still 100% reliable for me.

I have also tried gently warming the xBuddy and Loveboard boards with warm air at 37C from my wife's hair dryer. Thirty seconds of warm air directed onto the xBuddy followed by power up gives a fully functional system. Warming the Loveboard had no effect.

The problem is still present in firmware version 4.7.1. It can again be worked around using the warm air approach. I have not tried the "wait for 10 minutes then reset" approach on 4.7.1. I am to go back to 5.0.0-RC or later anyway.

The heating may have slightly affected timings which could have an effect on some sort of race condition in the firmware.  I wonder if putting a printer without this problem in a chilled room (or maybe using a freezer spray) would make the problem appear.

RE: Load Cell & Filement Sensor Errors

I am having this sam issue.

Unplugging the board and plugging it back in worked perfectly.

Hopefully it's fixed not fun having to do that each time I shut down.

Get a firmware update that may be able to reset the connection on start up without physically disconnecting the board.

RE: Load Cell & Filement Sensor Errors

So glad I found this as it would never have occurred to me to unplug the love board connector - My issues have been exactly the same as Chris - support are looking into it but are not able to help at the moment - I when though the issue (load cell filament sensor and sometimes the hot end fan), I've been though all the wiring and connectors very carefully but can't see an issue and in addition to this after printing 2 models (about an hour) I cycled the power and it when straight to the startup wizard (not the home screen) and failed on loadcell time out - I didn't touch any of the wiring or hardware. unplugged the love board connector and it went through the setup wizard just fine - I did also try the reset button after this when it was at all working and it when straight to the home screen as it should and nor the startup wizard. Anyway I'll add an update if I get a response from support. I did also send them a link to this thread so they know its not a one off and there is either a hardware or (hopefully) a firmware issue