I have an AMS 2 that was delivered with a new printer 2 weeks ago that has developed a fault whereby the AMS always thinks there is filament loaded in slot 1 but no filament is present.
I have taken the AMS apart as per the YouTube video from Bambu and can 100% confirm that there is no blockage in the (as support has called it) ‘feeder funnel unit’ or any of the tubes running from the feeder funnel unit to the outlet on the back of the AMS. If I try and push filament through the AMS 2 pro manually, this goes all the way through to the back and stops at the filament motor at the back of the AMS. With the AMS dismantled, I can push the filament all the way through with no issue at all.
I have reported this to support and they have advised that it sounds like the filament sensor in the feeder funnel unit in slot 1 is defective and will be sending me out a new feeder funnel unit. They asked for more info on my ticket like address and serial number before this was actioned and sent it over to them.
As I had a bit of time today, I decided to swap over the feeder funnel units from slot 1 to 4 and 4 to 1 expecting the fault to follow and be present on slot 4, but it did not. The fault stayed with slot 1 so guessing this is a firmware issue with the AMS mainboard.
I tried factory resetting the H2S and it would not let me with the AMS 2 connected as filament was detected in slot 1 as per the fault. I disconnected the AMS, tried a factory reset and this went though. After 30 mins of calibration, the same fault in slot 1 was still present.
As Bambu does not give us the firmware to be able to download from their site, I am now stuck with a software issue with my AMS and just waiting for support to check my ticket.
Just to not as well the using the side spool on the printer works AOK when manually feeding in the filament.
Not too sure if anyone else has had this issue but would be nice to be able to run a factory reset on the AMS 2 pro unit or the ability to download the firmware for the AMS or H2S to be able to self flash it from USB. Just seems a bit of a silly limitation to have not being able to flash the firmware ourselves.
If anyone has anything else I can try then I am open to suggestions and will update this when I hear back from support.
So after another email exchange to support, they thought it was the internal hub (bit in the bottom centre all 4 filament tubes go to). I have just received the new one, plugged it in and re-assembled the AMS 2 and all is working great now!
It did get me wondering what the issue was caused by so decided to take the old centre hub apart.
I first took of the sensor board on the top very carefully as I was guessing there would be small magnets in here to turn the sensor on and off and I was correct. They are accompanied with a spring on each that proved to be really fiddly! (understatement), but did notice that one of the really small springs under the sensor board once taken off on top was fitted sideways rather than upright as the others were. I also checked for bits of filament and none were present. While trying to put the spring back in, I knocked the centre hub and all of the magnets jumped out and stuck together. Luckily for me, I was working over a box as I didn’t want to loose any bits and luckily, I didn’t. Honestly, this is an absolute ar$3 to work with and can see why support sent me the complete centre hub rather than trying to take it apart and check it out. Finally managed to get this put back together after working from one side to another; putting the magnet in then the spring, then covering with a plastic store card and doing the next and so on until they were all fitted. I then slowly slid the store card away and screwed the sensor board back in place. Passed a piece of filament through and all worked AOK. I then tested it in the AMS once all re-assembled and all worked AOK.
Now filament loads in first time in slot 1 rather than multiple attempts to load and can only guess it was like this from new. The printer has been solid but the AMS 2 pro has been a right problem child. Seems like a Friday afternoon build to me as another issue I had was the main internal part that should slide and fit in to the bottom of the AMS was not fitted right and only found out when I tried to fit some desiccant holders for the AMS and they didn’t fit.
Lets hope it is smooth sailing from here but at least I know how to completely dismantle my AMS pro for the future.
I hope this helps someone but all I’ll say is if taking the sensor board off of the centre hub, make sure you do it over a box in case the magnets and springs jump out!
I have exactly the same issue after 200 hours of printing. Sensor slot 1 thinks there is filament loaded when there is not. I’ve taken the AMS 2 unit apart and there are no broken bits of filament, blockages or damage. Looks like I’ll need to go to support
So I took the internal hub out as suggested above (yes, springs and magnets fly out so watch it!) … then I carefully put back each magnet and spring covering each slot with the circuit board as I moved along from left to right.
Now it works! So, it’s not an electronic issue (as such) but the magnet and springs can become dislodged - so this is a bad design flaw! (BambuLabs please take note!)
I lost a large 3 day multi-colour print so I’m not very happy I hope it doesn’t happen again.
I just had the same thing happen, but mine was slot 4 that wasn’t working. I took out the one screw on top of the PCB and noticed the spring was on it’s side. My AMS always thought there was a piece of filament in the unit, so it kept pulling the filament out and would not load. Once I fixed the magnets/spring, it works great. But you’re right, those magnets like to jump out and stick to each other, and then you have to be really careful of those tiny springs. Good job getting it fixed. I can also take my AMS apart with my eyes closed now!
Glad my write up is helping, but as more and more people are having the same issue, sounds like a design flaw and hopefully Bambu Labs is monitoring the forums and makes some changes for the next AMS or updates the part to like a v2 of the centre hub.
It really is ball-ache stripping the hub down to the magnets and can understand why this part is just sent out as it requires a fair bit of time and effort to to try and reseat the springs and magnets.
let’s see what @BambuLab comes up with to resolve the issues going forward.
I am literlly having the same issue, unit ran flawlessly for about a month and then thew an error of “spool jam\filament stuck” checked all the tubes through the AMS through the AMS hub (i run and HT also) to the extruder, no blockages, no chaffing, no damage i can see. Went to the wiki as i cant get any response from Bambu in any way other thn the “Live” ai crap chat. I have also swapped lane one with lane four grabbers and the problem stays in Lane one.
Take the Pro 2 out of the system and the HT and printer (P1S) run flawlessly, but with it in the system I can see the HT but cannot use it (probably because of the error sate?)
I am really struggling with the lack of communication and the dependance of “us” to work on brand new equipment
Also side note…….I cant even figure out how to generate a post here lmao
they have a couple more days to make an attempt at communication or I may have to talk to the PRUSA people …..christ
Just had the same thing. This time Bambulab support insisted on me taking apart the hub. Taking it apart is okay, but putting it all together again - with these flimsy seals on the sides - really is a pain.
Seeing that getting broken filament inside the hub is such a common issue, this should be way easier! The hub should be fully serviceable from the top. I told them as much.
For the next guy: when reattaching the hub, make sure you don’t push the hub too much in. You need to align the screws with the plastic struts on the sides (I wanted to insert photos but they don’t allow those).
Also reattach the cables before mounting the hub. This way you can apply proper counter-pressure on these delicate connectors. This is advice from the helpful YouTube video “AMS 2 Pro Internal Hub Replacement” by 3DRevolution, the guy broke his connector clean off.
I think I might have this same issue and wanted to check if my symptoms are the same. This is an AMS 2 Pro and P2S I purchased a few months ago.
Slot 1 thinks there’s filament when there’s not. But the issue prevents me using any of the other slots, too: When I load filament into any slot (say, slot 3), this happens:
Sensor detects filament in slot 3, and does the usual brief back-and-forth with its motor.
Rollers in slot 1 spin for about 20 seconds.
Motor in slot 3 does a weird clicking thing for about 30 seconds.
Motor in slot 3 stops but fails to read RFID tag on the spool.
AMS now registers unidentified filaments in slots 1 and 3.
I created a video of the problem but the forum won’t let me link to it…if you want to assemble it yourself it’s youtu dot be slash Lp7BZu5ITdk.
Just about anything I do with the AMS right now results in some combination of that 20-second roller spin and 30-second clicking thing. Is this what y’all experienced or is it something different?
