Second Layer issues
I was printing... well, I forget what, now, but in any event, my nextruder started making the most horrible noise that sounded like a car trying to start with a dead battery. I opened up the idler, and there was no filament in it, but the filament wouldn't come out of the extruder. Eventually I was able to pull it out, but afterwards, I've been unable to complete a print. The first layer comes out perfectly, but the second is a completely splotchy mess. I've tried this with two different nozzles (0.6mm, then 0.4mm), and two different filaments (both PLA), and the pattern is exactly the same in either one:
My best guess is that something is restricting the volumetric flow, so that when the printer speeds up for the second layer, the extruder isn't keeping up, but I can't figure out what that might be at this point. It's not the nozzle, I don't _think_ it's the extruder. I did remove the planetary gears and clean and return them (with the PG alignment tool) to their housing, but nothing seems to work.
I'm perfectly willing to accept that I broke something, but for the life of me, I can't figure out what to replace.