Page MenuHomeAleph Objects Inc

Uptick in the number of RAMBo failures
Open, Needs TriagePublic


Over the last 2 weeks we have seen a bit of an increase in RAMBo failures that can't be tracked back to direct damage. Two of the boards were even been brand new. I have included the Serial Numbers for the printers where it was the original board and the sales orders for the boards that were purchased separately from a printer.



We may want to investigate this further. This might be tricky to track without being able to identify each board by a batch though. Any thoughts or input appreciated. Thanks!

Event Timeline

DaniAO assigned this task to kent.Jul 1 2019, 11:05 AM
logan changed the edit policy from "All Users" to "LulzBot Hardware Products (Project)".Jul 1 2019, 2:09 PM
logan removed a project: Redgum.
DaniAO added a comment.Jul 1 2019, 2:12 PM

going to remove redgum for now as it's not effecting them. We can always add it back should we see any problems.

kent added a comment.EditedJul 1 2019, 2:43 PM

Helpdesk ID reference:

205414 -- part cooling fans not working after customer RAMBo replacement. Recommend checking output of the fan circuit at the board instead of at the end of the harness to determine if it is the board or the harness.
205649 -- Incorrect Y axis spacing leading to probe sequence failure. Re-assembly issue not a RAMBo issue as far as I can tell.
198906 -- Y axis not moving.
206367 -- bent toolhead connector pins
205305 -- "Y axis not moving at all on their old Rambo, purhceased a replacement, and the issue persisted" <-- from the ticket. Because the issue persisted this is probably not related to the RAMBo (unless they got really unlucky and got two bad ones in a row).
193623 -- Y bed power harness melted at screw terminal clamp. We are close to the edge of what that connector is rated for with our bed power draw. This is probably shipping related where the connector backed off or wiggled enough that the metal tabs inside loosened up leading to a high current density and large power dissipation. @mjpelletier
this may be something to look into for future versions of PC boards.
201230 -- this customer has an inexperienced lab tech that I suspect is misdiagnosing issues and disassembling and then incorrectly re-assembling their printer.

In speaking with Kent, this is not so much a vendor quality issue as the errors relate to other issues. These units were tested prior to leaving Aleph and passed. Some of the RAMBo's were installed by Customers which could lead to problems. Some of the tickets are not RAMBo issues but other issues with the printers. If it is truly an electrical issue can @mjpelletier look at the tickets and see what his conclusion is?

Steven added a subscriber: Steven.Jul 3 2019, 7:02 AM

@sherylb @kent can you have those specific boards sent over to R&D so @mjpelletier can look at them once he is back in the office?

@Galadriel where are the boards located? We can send them to Mark.

Some of these helpdesk issues resulted in RMAs, so they are going to be down in MER on the green pallet in machines awaiting repair, or if they have already been repaired, they will probably be in the electronics scrap bin.

kent reassigned this task from kent to Galadriel.Jul 10 2019, 7:36 AM
kent added subscribers: franklin, EricNugent, logan, kent.

@Galadriel can you make a list of RMA's that resulted from these RAMBo issues and post it here? @MikeR @bigmansas @oliver @zachah @logan @EricNugent @franklin if you repair one of these RMA's hang on to the boards so we can give it to @mjpelletier and he can do some failure analysis.

I have another customer (ticket ID 81753) with a failed RAMBo after a week of installing.

I don't want to give him a solid answer if we can cover it or not until we have a solid answer here.


@kent @mjpelletier @sherylb
Is there an estimated timeline for figuring this out?

@TyTh we still haven't received any known failed boards in R&D to look at. @mjpelletier is back in the office on Tuesday so if we have a few of them to look at by then we can look them over.

Galadriel added a comment.EditedJul 12 2019, 7:29 AM

@kent Here is a list of RMA's that resulted in either a printer coming back or a board being sent out:

I don't think RMA13336 would fall under a manufacturing issue with the board, it seems more like a loose connector built up resistance in that area and overheated it burning the connection. That is just my guess based on the photos though.

kent added a comment.Jul 12 2019, 8:12 AM

@mjpelletier @Steven Please let me know if you find a quality issue with these boards when we get a chance to look at them.

@kent @mjpelletier @Steven New one to add to this list, ticket ID 207,731. Customer bought a new 1.3L RAMBo from us and it came with pins missing, based on photos looks like the pins were never installed. Reference for purchase of board: SO103180.
We will be sending customer replacement board, would you like us to get this one back so we can check so serial number on the board or anything?

logan added a comment.Jul 12 2019, 2:37 PM

@Galadriel Ouch! Missing 90% of the LCD header. Have you suggested upgrading to 1.4? I'd send them the harnesses free of charge at this point given their trouble, personally.

logan added a comment.EditedJul 12 2019, 2:38 PM

Nevermind, I now see that it is a TAZ 5 so that wouldn't be as straightforward. Disregard

lisa added a comment.EditedJul 15 2019, 12:39 PM

A customer is talking about this on social media. Referred to Ty to get more info and resolve his issue.

This is the customer from ticket ID 81753, mentioned above

@kent @Steven @sherylb
I am in the process of sending a new RAMBo to the customer above. Would you like to get the old one back for testing?

logan added a comment.Jul 15 2019, 3:19 PM

Since he's seeing the exact same issue as before the RAMBo was swapped, has everything else been checked? Specifically the internal and external bed power harness that @kent suggested checking in the ticket, which is a common failure point. If that hasn't been checked you should consider sending the new one-piece version along with the RAMBo.

I have already set up an RMA to send him the new one-piece as well.

I am currently going back through the instances of failures listed above in a bit more detail and thus far I have found at least 1 additional issue that I listed that upon closer inspection looks to not actually a RAMBo issue. I wasn't able to get through everything today so I will have to finish and update this on Friday when I am back in. I just wanted to update to make sure that people knew it is still on my radar and I should have things better situated on this ticket on Friday. Sorry for the delay!