Zero extrusion for the first two layers
I've encountered a strange error and I'm at my wits' end. After one big print failed when the object fatally warped, now the MK4S won't print the first two layers. The head moves, "scratches" the plate, but something starts to flow from the nozzle starting with layer number 3. It does this with all models and all materials without exception, including g-codes that I had saved on a flash drive and that printed correctly in the past. The pre-printing processes, including nozzle cleaning, run completely normally. So far, I have tried:
- Disassembling and reassembling the entire hotend, including the gearbox.
- Reflashing the printer firmware to a lower version and then back to the newest (the error occurred in both versions).
- Performing a default factory reset.
- Repeatedly running all calibration tests.
- Repeatedly changing the filament.
Nothing helps, and I don't know what to do anymore. For now, I'm "coping" with the error by printing everything with a 2-layer high raft, which in practice means that the object is printed at the correct size, but the first layer at the bottom is obviously ugly, and the plate also suffers quite a bit.
If anyone can advise, I would really appreciate your help. 🙁