Light pattern after calibration shown.
Highly frustrating and I have maxed out my Claude AI limit for the day trying to solve.
BMCU 370 X worked fine (electronically) on my Bambu A1- I upgraded because I was sick of burning out worm gears.
BMCU 370 C DM built via an upgrade kit and a new motherboard/daughterboard. I know the old motherboard should work but I burned out a motor channel doing some testing with a bench power supply, oops.
I have tried PJARZCAK firmware for BMCU 370 C versions 1.03, 04 and 05 (autoload, rgb on, solo, 0.095) - with the same problem. The printer wont detect the BMCU and only channel 3 actually moves the motor based on input from the buffer.
Slot colors visible in photo, but heres a breakdown of what it does after calibration
Slot
- Top led red, no response from buffer push/pull
- Bottom LED yellow, bottom LED turns blue on buffer push then turns yellow, no motor response
- Bottom LED yellow, bottom LED turns blue on buffer push then turns yellow, motor works both ways
4)Bottom LED yellow, bottom LED turns blue on buffer push then turns yellow, no motor response
NOTE- plugging my 370 x board connects to printer fine (I didnt connect the daughter boards) , then i flashed the 370 x board with the C DM firmware and it no longer connects to printer - making 2 x motherboards that wont connect to printer on this firmware.
Second note - I read that some printers require switching the signal A and B lines. I interpreted that as the yellow and white wires carrying just over 2V DC, NOT the 24V red and black. I tried switching those and nothing changed except the MB led stayed red at startup, never turning white
A1 is running preban firmware 1.04.00.00 - not sure if that is a problem, I understand the newer BMCU firmwares are compatible with newer Bambu firmwares, I didnt see anything about them potentially losing support for Bambu firmware.
Please give me an assist! This is my daughters printer and shes now taking over my X1 while hers is down!