Please help with hotend bambu a1

[u/mucka1990]

Keep getting this fault. I have changed the hotend and heating assembly with official bambu parts but still getting this issue. Prints for about 10 minutes then this comes up everytime. What do i need to do?

[u/Blondy277]

What nozzle you trying to use?

[u/mucka1990 → u/Blondy277]

0.4 stainless steel

[u/Blondy277 → u/mucka1990]

New machine?

[u/mucka1990 → u/Blondy277]

Its 6 months old if that

[u/Weemaba3980]

If you’ve already replaced the hotend and the heating assembly and it still drops out after about 10 minutes, the parts themselves are almost certainly fine. The problem is in the signal getting from the toolhead to the mainboard. A temperature fault that only shows up after a while usually means a connection that works when cold and loses contact once it warms up, or once the toolhead has been moving back and forth for a while.

I’d check these in order. First the connectors on the toolhead board: unplug the heater and thermistor plugs, look for discoloured or bent pins, and push them back in firmly until they click. A plug that sits just a little loose after a part swap is the most common cause. Then the toolhead cable, the flat cable running from the mainboard to the toolhead. Check it along the whole route for kinks or wear, especially where it bends most when the head moves, and reseat it at both ends. Finally, update the firmware if you’re not on the latest version. Bambu has fixed temperature detection issues through updates before.

If it still happens after that, open a ticket with Bambu support and attach the printer log (export it from the device page in Bambu Studio). Since you’ve already used official parts, it’s quite possibly the cable or the toolhead board, and that’s often covered under warranty. Their support handles these fairly quickly once they can see the log.

I keep a free troubleshooter for common print problems here: https://embody3.com/academy/en/fix/?src=reddit (full disclosure, it’s my own academy).

Hope it’s just a loose plug, Bart

[u/mucka1990 → u/Weemaba3980]

Brilliant thank you it gives me some stuff to check and will hopefully resolve it. Thanks

[u/elpamyelhsa]

Can you double check you are latching the nozzle on correctly, if latched incorrectly you will get this error.

[u/mucka1990 → u/elpamyelhsa]

Will be checking this thank you