Just to clarify up front: I already ordered replacements and I'm not looking for repair advice. What I want to know is how the hell did this happen, and more importantly, how did it happen on two different machines?
The setup:
- Two H2D machines, one a few months newer than the other
- Runtime: ~3500 hours and ~2000 hours
- Recent print history: ASA in the past, but only PLA for the past several months
- Both were printing PLA when they died
Both failures happened identically: during a dual-nozzle print, the printer switched to the right nozzle and then failed to heat the left back up when switching back. On one machine, power-cycling temporarily "fixed" it until the next print attempt. The other started always reporting a broken left assembly on boot. When I pulled them, both were charred and melted — pictures attached.
Things I've already ruled out:
- Each machine is on its own separate UPS
- No weather/electrical events in the area
- Everything else in the house is fine
- Both on current firmware, no recent update
I keep flip-flopping between "weird coincidence, bad batch of heater cartridges" and "this could have started a fire." Two independent machines, same component, same side, same failure mode, within 48 hours... that's a hell of a coincidence.
Has anyone else seen this or heard of it?