Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job  

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

The skipped steps are definitely unrelated.  The carriage is actually contacting the front of the left Y axis at Y=-9, and it doesn't lose steps at -8, so it's definitely a separate issue.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

I did some testing, swapping heat bed cables and channels, and the error continued to occur at the same point in the job, and stayed with the physical tile, even when it was connected to a different channel with a different cable.  Prusa Chat determined it is likely the tile and will replace it.

I still don't understand why it was occurring at the same point in the job (2 hours in, on the same layer, within a couple of millimeters).  It has also only occurred with that one job, three times in a row.  Other jobs that use the same tile, at the same temperatures, over more than 2 hours have always completed successfully.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

I'm getting the same error, and replacing the tile didn't fix it :-(. 

What bed temps are you using?  My printer only fails on the higher bed temps of 100C with ABS.  

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

PETG in my case, so I think 85C.  I have the new tile, but I haven't seen the error on any other job, so I don't believe it's really the tile.

I think I'm going to hang on to the tile and only install it if/when I have another reproducible case so I can A/B test the repair.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

Posted by: @clough42-2

I still don't understand why it was occurring at the same point in the job (2 hours in, on the same layer, within a couple of millimeters). 

I had a weird error when I first got my XL where one tool would show a temperature error on the thermistor. The thing that threw me at first is that it happened in the exact same spot on a large 5 hour job. 

The problem turned out to be a weak underpowered nozzle heater. I calculated it was drawing 30 watts instead of 40 watts and that was enough. The problem manifested itself during maximum extrusion volume with a hot filament (PCTG). Chat support was about as useful as a box of rocks. They refused to acknowledge that the heater could be to blame and kept trying to dump me. I ended up just buying the part myself and it fixed the problem.

So having the problem at the exact same point could be due to whatever stress is on the system just coming to the failure point at the same place each time.

I won't use chat support anymore because they seem to be people who follow a script, and really have no idea what they are doing. They're main purpose is to get rid of the support issue but not to fix it. Email support seems to be more intelligent and from someone who actually knows how the system works.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

Oh, interesting.  That's a possibility.  If I ever see the error again, I'll swap in the tile and see if it fixes it.  I actually overwrote the specific project file that was causing it reliably, and other, similar projects don't seem to cause any issues.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

My tile error happens on any print on that part of the bed no matter what print it is, so it may not be the same problem you're having.   

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

I am seeing the same behavior but suspect it is caused by heat injected from the print.  I am printing with PA6-CF at 290C with the bed set at 50C. I kept getting an error on tile 3. I swapped connectors and the error occurred again at the same point in the job on the same physical tile, (now called tile 4) where the part was centered.

I moved the part on the print bed and the error moved to the new tile where the part was now centered. This indicates to me that the temperature differential is big enough for the bed to pick up the heat from the print and report an error. I've not had this before, but this was the biggest difference between nozzle temp and bed temp I've ever used.

I've yet to engage support, but there is a ticket logged for this issue -> https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/3484

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

So this is an interesting thread. I’ve had the same issue when printing TPU. Interestingly enough I even turned off the heated bed since TPU doesn’t necessarily need it. The same error occurred. Temperature spike on the bed. Which doesn’t make sense to me at all given the bed temp should be ambient. Going to decrease the gap between the heated bed and filament and see if I can continue to reproduce the problem. Not sure if this is a hardware or firmware issue. 

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

I've had the same issue from day one with this printer. I have spent hours with Prusa Support to no avail. They finally sent me a new heat tile, new heat bed board, and cable. Still had intermittent failures on multiple seemingly random tiles. Prusa Support had me get out a multimeter and check the PSUs, both of which are perfectly fine. I hate this printer at this point because I can't ever be sure it will complete a print. I have exhausted supports troubleshooting and my printer still doesn't work right. For the money that the XL costs, I feel that Prusa should take it back, but I know that isn't happening.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

I started getting this error after Prusa sent me the enclosure, installed it, and trying to print ASA. My print is over the tiles in the middle but I get the error on tile #7 which is to the front left. It makes no sense.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

I don’t have the xl so take this solution lightly. 

Temp errors are most frustrating. They may not relate to the bed tile at all. It could be an issues with any of the heater wires or thermistors.  On other printers this involves me having to go through and check everything to find where the fault is. 

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

Tile 7 is one that connects directly to the psu, The troubleshooting guide says that may be a psu issue. 

I got the printer set up last night after work. I had no issues with any of the sensor checks or heatbed. I printed a tiny mount for my ESP32-s3-eye in the center of the bed without incident.

Next I tried running a full bed 22 hour print. About 20 minutes in I got this error on tile 4.

1. I ran the heatbed check again with no issues found. 
2. Per the troubleshooting guide, I swapped the tile connectors for tile 4 and tile 8, and the error happened on "tile 8"(tile 4 on port 8) instead.
3. I swapped the other ends of the cables(now tiles connected to stock port, but cables are swapped), and the error returned to tile 4, indicating a likely tile issue.  
4. I then preheated the bed to PLA temps for 30 minutes without issue. 
5. I then cut out the part that was printing over tile 4, resliced, and re-printed. This time the error popped up again, but on tile 16....

I've contacted prusa info via email, and ordered a spare parts kit and extra tile in parallel, but hoping this can be resolved with a setting or something faster than the shipping from Prague to the western US, especially with customs delays. I'm anxious to start using this printer that cost more than my first 4 cars combined.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

I had this issue yesterday on an ASA print (100°C bed). Original PR enclosure installed, doors closed and enclosure fan running. I had done some longer ASA and ABS prints with no problems. In my case it was the print fan. I wanted to try if PETG can be used for ASA support (turns out it can't, it sticks too much). The error occured on the layer where the print cooling for my PETG supports kicked in. The print was about one tile in size, I could move it around and get the error at +/- 1 layer.
Its kind of funny, I was using tailormade supports (basically a blocky cradle the print was sitting on). No bottom layer and grid infill on the supports.
More bottom layers -> problem gone
Cubic infill, more infill % -> problem gone
Cooling off for PETG -> problem gone
reduced PETG speed -> problem much worse, error appeared earlier

My theory is the support structure was piping concentrated colder air towards the bed. No cooling on ASA, so it starts fluctuating only when supports are printed (I actually saw this, temp immediately dropped 2°C). At 100°C this matters more. I can definitely see some more normal prints doing this as well, sometimes you hear the wind noises from taller prints if they have channel-like structures or not much infill. The bed heaters can't compensate very fast... My ultimate solution was to start PETG cooling only at > 10 layers then increase incrementally. That removed the problem and the print completed, then I found out PETG+ASA doesn't work 🤣 

TLDR; try switching off the part fan and see what happens

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

Posted by: @ntdesign

I had this issue yesterday on an ASA print (100°C bed). Original PR enclosure installed, doors closed and enclosure fan running. I had done some longer ASA and ABS prints with no problems. In my case it was the print fan. I wanted to try if PETG can be used for ASA support (turns out it can't, it sticks too much). The error occured on the layer where the print cooling for my PETG supports kicked in. The print was about one tile in size, I could move it around and get the error at +/- 1 layer.
Its kind of funny, I was using tailormade supports (basically a blocky cradle the print was sitting on). No bottom layer and grid infill on the supports.
More bottom layers -> problem gone
Cubic infill, more infill % -> problem gone
Cooling off for PETG -> problem gone
reduced PETG speed -> problem much worse, error appeared earlier

My theory is the support structure was piping concentrated colder air towards the bed. No cooling on ASA, so it starts fluctuating only when supports are printed (I actually saw this, temp immediately dropped 2°C). At 100°C this matters more. I can definitely see some more normal prints doing this as well, sometimes you hear the wind noises from taller prints if they have channel-like structures or not much infill. The bed heaters can't compensate very fast... My ultimate solution was to start PETG cooling only at > 10 layers then increase incrementally. That removed the problem and the print completed, then I found out PETG+ASA doesn't work 🤣 

TLDR; try switching off the part fan and see what happens

I've not this error before.  I didn't know if this helps, but I never print on a single tile for a couple of reasons.  

- I think the total bed mass is to big for a single tile heater to keep stable.

- I feel the bed warps more the with fewer tiles turned on. 

I purposely place objects so that it touches at least 4 tiles.  I can't say whether or not this will help, but if the issue really is the coming from the fan more tiles will help. 

I'll also note that I always turn on the bed to printing temperature for about 30 minutes before ever starting a print in order to get the frame and everything warmed up.  As the bed and frame warm up they expand and move.  This causes the shape of the bed to change.  So by letting everything warm up you get the best bed mesh possible.  This is especially noticable if you do any prints where you print the parts sequentially, aka complete an entire part before starting the next.  I've had first layer issues when doing this on the parts printing after the first.  This is because the bed shape changed since the bed mesh was made.  I've solved this by a long preheat and lowering the live z some.  It makes for a little bit too squished first layer on the first part, but solves the issues for the sequential parts.

This is definitely not the fix for some of the other cases in this thread, as those seem to be defective parts.

I've done 20+ hour ASA prints inside my enclosure and haven't run into this.

Good luck.

RE:

What you say is correct, but does it actually heat only one tile? I have no IR camera, but I think I remember reading somewhere that tiles neighboring the print are also heated. Has anyone checked?
My part placement wasn't based on tiles but on the sheet markings. It's unlikely I was really only touching one, especially since I moved the print around a few times. That said, it seems to make no difference e.g. when I print only in one corner (where mesh distortion should be worst). I forgot to mention I preheat about 20mins with closed doors before starting ASA prints. I don't know if this really matters, but the error happened anyway. ASA cooling settings are less aggressive than PETG, and I never had issues with pure ASA prints so I figured it might be that.

This is definitely not the fix for some of the other cases in this thread, as those seem to be defective parts.

I fully agree. Some are clearly hardware issues.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

Posted by: @ntdesign

What you say is correct, but does it actually heat only one tile? I have no IR camera, but I think I remember reading somewhere that tiles neighboring the print are also heated. Has anyone checked?
My part placement wasn't based on tiles but on the sheet markings. It's unlikely I was really only touching one, especially since I moved the print around a few times. That said, it seems to make no difference e.g. when I print only in one corner (where mesh distortion should be worst). I forgot to mention I preheat about 20mins with closed doors before starting ASA prints. I don't know if this really matters, but the error happened anyway. ASA cooling settings are less aggressive than PETG, and I never had issues with pure ASA prints so I figured it might be that.

This is definitely not the fix for some of the other cases in this thread, as those seem to be defective parts.

I fully agree. Some are clearly hardware issues.

Good point, I'm not sure what the logic is on the bed tiles for heating.  You can't really tell from the small graphic on the display.  Maybe there's another way to tell. 

I try to get the enclosure up to a minimum of 35° C before starting any ASA or ABS prints.  That usually means like a 50 minute preheat minimum for me, but my printers are in a 72°F temperature controlled area so it may differ for you.  I shoot to have the chamber temp at 40-45°C when the part starts to build up. 

I honestly wish we had more control in the slicer over the heatbed tiles.  I'm sure you could do a custom write in gcode, but I haven't went that far yet.  I've in some cases I've put a self made purge tower somewhere else on the bed so that it would use more tiles since I didn't have any active chamber heater other than the bed. 

I also don't like the preheat function on the printer itself because it just turns on everything.  I do it manually under the control menu.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

After replacing tiles, wires, and spending hours with support, my ultimate solution was to heat the entire bed. Problem solved and hasn’t ever returned.

RE: Repeated Modular Bed Error (unexpected temperature peak) at the same point in the job

With the original PR enclosure I found it best to reduce the fan speed. Default is 80%, but then heating the chamber to 40°C with the bed idling at 100°C takes forever. I reduced it to 60%. 10 minutes preheat, followed by the normal 10-11 minutes absorbing heat is enough to get dimension-accurate ASA prints that stick to the bed.

I had the error again tonight, I briefly opened the door to take a foto and the front right tile failed. It was only a small print, but it sucks so much you can't recover from this error. It should just pause and see if it stabilizes. Anyway, they can probably fix this in firmware and maybe it is even a new bug considering I never had this with 6.0.4.