Today is June 24, 2026, and I decided to describe a real solution to this problem. It’s all about the extruder motor and its wires.
I tried a USB board for the print head, and the result was the same.
In desperation, I started grounding the hotend, motor shaft, and gears, and suddenly realized the extruder motor was the ONLY part I hadn’t replaced. I bought a new one and turned it so the wires were on top (the first build had the wires running underneath between the motor and the board). And the problem disappeared—no USB reboots, no RP2040 reboots—everything just works.
This is the WRONG solution (it worked for a month or two, and then the problem returned):
Ok. Some news. I got a new EBB2209_RP2040 board and replaced the old one. And this didn’t help - the first print failed on the 40th layer.
Then I decided to add a capacitor to the ebb power line (I found only a big 470mkf-100v so I soldered it to power input contacts and it seems to me this helps - I printed 1.5hour part and then 2hour parts set.
So I think the cause is a voltage drop on power wires because of the toolhead payload: 70W heater block, 3xfan, pt1000 with max 31865, 3 bright leds and extruder drive (650ma). There is only one large capacitor on the ebb board - 100mkf-35v and it looks like it is too small for this load.
