Bambu Lab is once more in hot water after user Moreiras3D posted a video of a melted A1 3D printer to Instagram. The footage shows an A1 with its side completely melted down to the metal chassis, but some of the key details behind the incident remain unknown. The resulting heat appears to have been powerful enough that another A1 sitting next to it has a damaged cord.The video itself does not explain what happened, and plays a Contemporary Brazilian gospel soundtrack. The second half of the video shows a young boy unboxing a new A1 while watching an assembly video by StlFlix, who also hails from Brazil. The comments are mostly in Portuguese, but sifting through them with the help of Google Gemini to translate, we get some of the story.“My machine has been in use for 3 months and already has recent reports from several others that the same thing happened,” said Moreiras3D. In a follow-up reply, he notes the printer was on a surge protector, but that the fire started on the machine itself, not the outlet.At first glance, it would appear this is the result of a faulty NTC thermistor we reported on in January. At that time, YouTuber Grant Posner (3D Musketeers) was finding an alarming number of A1 printers with charred or melted cases, but none appeared as severe as this one from Moreiras3D.The known issue stems from the A1’s AC power distribution board operating above normal temperatures and posing a risk of fire. The AC power board uses an NTC thermistor to limit inrush current and is active only while the printer is rapidly warming up. Bambu Lab responded that no fires had been reported at that time, and that its printers comply with applicable safety standards and use flame-retardant materials. The company also said it would fix the issue on printers going forward.