RE: Load Cell & Filement Sensor Errors
I've only had my MK4 for two days and it's been doing this to me since the beginning. I have noticed that I just have to wait about half a minute after first turning on the power supply and then turn the power supply off and on again and the problem is over. I guess the delta electronics power supply is of poor quality and charges to operating voltage slower than the control electronics.
RE: Load Cell & Filement Sensor Errors
I'm glad to read that there are many more MK4 users with the same problem. I have been chatting with various employees of the Prusa service desk for a week now, and again and again they go through standard protocols, and so far no progress has been made.
Today I sent an email and pointed them to this forum thread, in the hope that they will see that a whole batch of printers here may have a problem with the filament sensor and the load cell sensor.
It is now clear to me that it is not the sensors themselves, but the problem must be found either in the love board, or in the Nextruder cable or on the xBuddy board. I personally suspect that something is going wrong on the xBuddy board due to shrinkage and expansion near the Nextruder connector. After about 10 to 20 minutes, the board has warmed up so much after switching on that it initializes the sensors after a reset. So it could well be a production fault in an entire batch of the xBuddy boards, which will sooner or later reveal itself to many more MK4 users.
I indicated in my email that Prusa's technicians and service desk employees should take their own web forum much more seriously and should actively respond to it, so that we, the users, know that they take us seriously and we do not have to go through those protocols again and again. which we have gone through so many times without results.
Hopefully it will yield something.
RE: Load Cell & Filement Sensor Errors
I've also brought this thread to their attention - My printer reliably says the loadcell is not initialised and the filament sensor disconnected whenever I cycle the power however you might want to check your loadcell calibration if you press the reset button. After removing and replacing the love board cable to get the loadcell to be recognised the value in the diagnostic window is 6500-7000, after calibrating the load cell the value is between -20 to -35 BUT if I press the reset button the value changes to around -720! I have seen reports of the hot end marking the build plate and so this might be OK but I have not run the printer without doing a loadcell calibration just to be on the safe side.
RE:
The problem is solved!
I wrote about the problem to support about 2 weeks ago and suggested that the LoveBoard or Hotend heatsink may be faulty.
After a few days I received both parts, yesterday I found time to replace them. I wasn't wrong, the printer works without any problems so far, I even printed 2 test prints from a pendrive.
I would rather believe that LoveBoard is to blame, probably a faulty batch. Someone wrote earlier that they replaced LoveBoard and xBuddy and still nothing, they probably got a part that is apparently defective again, some batch of parts that does not work, I would advise you to send the LoveBoard or Hotend heatsink again.
And don't try to heat it up with your wife's hair dryer, it has nothing to do with it, I tested the printer yesterday and today, it was turned on after the night and everything works. Loadcell and Filament sensor, everything is fine and the temperature of the printer in individual places after turning it on showed from 21 to 25 degrees, something like that.
We'll see after longer use if the problem doesn't come back, but for now it's OK. I wish everyone a successful solution to the problem.
RE: Load Cell & Filement Sensor Errors
Hi guys,
so here is my update. (more or less)
The package from prusa with the replacement parts arrived.
I replaced the xBuddy and the love board just now. And nothing.
The error still persists.
It seems to me that the cause may be a bug in the firmware. Maybe not initializing the sensors correctly or something like that.
RE: Load Cell & Filement Sensor Errors
@dawid thanks for the judgement on my use of a slightly warm (37C) hairdryer for thirty seconds on the xBuddy. It works for me. As does my usual method of letting the printer sit idle for a few minutes and then pressing reset. Making it do something like preheating reduces the time required before the reset. In my case, when I was monitoring the mainboard temperature sensor, once it had risen above 32 to 34C then the reset always worked.
I believe that this problem could possibly be permanently cured by a minor change to the firmware to take account of whatever variation in component tolerances is causing it in the first case.
RE: Load Cell & Filement Sensor Errors
Hi Chaps, Tech help have just emailed asking me to flash the latest firmware (5.0.0 - File https://help.prusa3d.com/downloads/mk4/firmware).
Having cycled the power a few times now this appears to have completely fixed the issue - the loadcell calibration is still changing from it's calibrated value (slightly negative) to around 8000 when I do a soft reset or cycle the power. I have asked if this is expected but in all other respects it appears to work.
Oh and I had already flashed RC 5.0.0 and that didn't work and so I thing there must have been a few changes.
RE: Load Cell & Filement Sensor Errors
The problem is now fixed for me after I upgraded to the final 5.0.0 firmware release yesterday.
RE:
For me the firmware update fixed the problem to. Both sensors are online after a cold start. But ther still is a strange issue. I too saw that the loadcel values ar way to high. So I calibated it. After calibation the filement sensor stops working. Rebooting, all is up again, but the loadcel is up in the 8000 again to. And after calibrating the loadcel again the filamentsensor stops working again. Leaving the calibration untouched, leaves the filamentsensor working. Anyone else seeing this beheavior?
RE: Load Cell & Filement Sensor Errors
The update has also finally solved the problem for me. Finally! The support team was also able to solve my Y axis. Now everything is clear.
RE: Load Cell & Filement Sensor Errors
firmware upgrade to 5.0.0 seems to have cleared up my loadcell not registering on cold startup. For the past few days the unplug/replug the loveboard cable on the xbuddy board worked. Have been leaving the printer on continuously for a day or two and it printed ok.
Prusa is sending me some replacement parts, I'm not quite sure yet what is coming as message was not clear from customer service and we discussed several options - I think loveboard and maybe hotend. I don't think loadcell will be included, we shall see.
I'll report back after parts arrive and are installed. but for now printer is working stably with the 5.0.0 firmware upgrade.
RE: Load Cell & Filement Sensor Errors
Hi guys,
it seems that the release of 5.0.0 have fixed this issue.
After taking a look into the sources and comparing the previous version against the 5.0.0 it looks indeed as there were some changes that affect the initialization of sensors. (Don't take this too seriously, I've just overflown the changes)
RE: Load Cell & Filement Sensor Errors
Hi, I have an update with my case. (@jan-riha reported on this for our printer).
We got new cable and love board from support and it worked after replacement (even with 4.7.1 FW). Also ok with 5.0.0.
Happy printing.
RE: Load Cell & Filement Sensor Errors
Hi
Something is wrong with my loadcell self-test. The Z azis goes up and then I get an error message saying the loadcell test has failed. There is no prompt on the screen that says "tap nozzle now", it just fails during diagnostic test.
I did try with the self test and same thing, i did not get the promt like step 5 in the Prefilight check.
Temperature went down to 49 deg C and then i got the failed message.
Firmeware is 5.0.0.
thanks