Comm error between P1s/Ams2pro-4x blinking lights

Have a problem on my P1S/ AMS2PRo combo, printed about 600 hours . Turned on the printer, lights on the AMS flash white on each feeder, does this in sequence twice then change to all blinking , two quick red blinks.

  • Found out this is a communication error between the AMS and the printer.
    Contacted Bambulab and they have sent a new main board for the AMS and a 4 pin and 6 pin cables. In the meantime I purchased an AMS interface board (pretty cheap)
    Changed the AMS main board and the two cables (continuity checked the original cables, nothing wrong with them)
    So turned it on, still blinking lights, no different.
    Went through the Wiki fault finding. 24vDC and ground from the rear port on the printer, SigA and SigB on the same port has between 4-6K ohms. Checked this up to the AMS input, all ok. Checked the resistance of the filament buffer when moving the sliding magnet, that is good. Fitted the new AMS interface card, still flashing lights, rechecked all measurements, all still the same.
    Green lights on MC board flashes every 5 second, so no faults according to that.
    I’m stumped. Whether I had a faulty AMS main board and been supplied with another faulty one I don’t know.
    Resent another ticket with more logs.

Has anyone had this problem? It’s been working fine since purchase OCT 2025

There is no fault code on the screen and it just says AMS is offline

yes had that one, could be a broken filament stuck by the sensors, unload all the filiments switch everything off, disconnect the ptfe tubes and see if there is something stuck buy pushing some filament in the holes, push down the button in the middle.

My AMS Pro has started acting up since I done the most recent bambu studio update about 6-7 days ago. One of the filament spools rewinds too far after loading the filament and pulls the filament out of the feeder. It also randomly stops drying after a very short time even though it is set for 12 hours. It threw up a couple of heating/drying communication errors a few days ago but none last night when it stopped heating 3 times.

I swapped the comms cable to the other port this morning and it’s currently on dry so will see if it stops or works correctly today.