No. You get no identification at all. Other than chambers start dumping powder and under dosing.
I spent a month troubleshooting chambers last time this happened till they mentioned that motor coupler…at least now I know and this time it only took a week of down time as I knew immediately.
Getting quite good at pulling the back of the Fuse apart…
do you always get the sink hole on the same area of the chamber?
I am assuming that somehow it is shifting the roller assembly diagonally, pushing a majority of the powder to the front side of the chamber, which overflows the left hand flipper on the front side but causing under dosing on the rear side. Does that match with the symptoms you see?
Happens on all sides.
Bottom line… whatever it’s doing… make sure your coupler is not loose.
Back up and running with a fresh motor swap.
IIRC you are running a 1+ now, did you ever have this issue on the Fuse1?
Well… after the third replacement motor, and only 6 half chamber prints, this fourth motor coupler obviously broke loose again.
Same pattern of underusing from the left to right pass and sink holes forming as before when the other two motor couplers broke loose.
This is even after getting the newly improved motor/coupler according to Formlabs support…but to me it looked like the same as the others…
Obviously there is something up stream causing these couplers to break loose from their “very sophisticated design” of a spring steel pin… 
Going to pull the printer apart after it cools to confirm…but at this point I am an expert at knowing when this happens…
There must be something else going on here in the system as you point out. That, or a large batch of bad motor assemblies.
Doing some searching I found this Formlabs troubleshooting talking about the motors
https://support.formlabs.com/s/article/Fuse-1-generation-motor-movement-errors-Error-90-93-94-and-95?language=en_US
I am currently running the Fuse 1+ but that’s what I found.
In it you can see them showing a video of the broken loose coupler which has now happened to 4 of mine, this last one after just 6 prints.
So this back plate appears to be a magnetic sensor.
I am wandering if there is something going on in the boards and/or calculations between the printer and that magnetic sensor that is driving it hard to one side or another and stressing/breaking the coupler loose…
Regardless, the design of this coupler with a simple spring steel pin through one axis and the “glue” they primarily use to hold it stiff…is a pretty weak design.
The motors are all the same part but interesting that they “updated” the Z motor from an older coupler to this new flimsy design…to me the older one looked more robust 
Now that I have a handful of these motors with loose couplers, I am thinking of trying to put one in my CNC mill to drill and tap out some set screws into it on the other axis…
I have already tried to tap out the spring steel pin on one coupler…but that didn’t happen. Assume I would need to apply heat as it seems to be also held in by the same glue that they rely on, on the shaft.
If you go through that troubleshooting page on motors…they definitely point this issue out…so I am not alone.
With it just moving the Recoater chain gear… I am either just extremely unlucky with bad motors or it has something to do with this magnetic sensor calibration on the back of the motor driving it hard to one side stressing it out…maybe…
But for anyone who all of a sudden starts experiencing back to back failures on all chambers…and it looks like this…pull your printer back off and check that coupler.
Wow, you really pulled the shortest straw when it comes to luck with your printers. Last time i had a sinkhole like that, i swapped the volcano seal on the buildchamber and presto. Now come to think of it, each time we get a carepackage included in the ESP there is always 2-3 recoater motors, i have quite the collection.
Only needed to replace two during the last two-three years. And we run four of these machines nowadays.
Hope you get it sorted, and keep us posted. It´s very helpful for us getting updates from you, i think we all agree on that.
Like I said, the first Recoater motor coupler that broke loose had me troubleshooting for weeks…with a Formlabs rep here on scene trying to as well. I swore it was my chambers due to the sink holes in the bed once it hit the thermal break level of the chamber but couldn’t understand why it started happening on “all three” of my chambers at once…
We were pulling apart chambers left and right trying to figure it out before realizing it was the Recoater motor coupler.
I have had to troubleshoot a lot with this Fuse 1+ and the original Fuse 1 over the years…but this one took us for a ride for sure and still obviously is.
The last motor that broke free, Formlabs Support didn’t even hesitate. As soon as I reported the failure they recommended I check the motor and had one in the mail…so this is obviously a common thing now.
Interesting you received motors in your service resupply… seems like we all get different things sent to us in these service packages
On a side note, whats your humidity level in your print room? Im just thinking if the coater is strained by clumped powder, i bet its a longshot but its Fuse 1, anything is possible.
30-36%….and 70 degrees. My shop is far more comfortable than my house.
I’ve been running a Fuse 1 then a fuse 1+ for a few years now…started with nylon 12 GF and ran that for two years…
I also ran Nylon 12 GF at a 70% refresh because it was needed for consistency and now Nylon 12 at a 45% refresh.
Not my first rodeo…
Being an avid reader of your adventure over the years I just gotta say that your machines doesn’t love you 
I cannot believe how much they like to fail with no apparent reason.
Well… Formlabs must have finally determined the same thing… because they just swapped out my machine for another Fuse 1+ and it is a night and day difference in just the way it sounds…the original was “clunky” in its movements whereas this one so far has been smooth and so far so good.
Only on my 3rd print…. other than a contamination issue from these stupid new “bags” of powder on my second print…everything is good..fingers crossed no more Gremlins! 
At least they finally are accepting defective machines back and providing this kind of support. I guess you were on full support and within the warranty period?
sounds like something got out of alignment
glad the took care of you. sucks that they didnt do it sooner.
