I've tried to print one part now perhaps 5 times.  Each time, something goes wrong, whether it is an extruder failure or a power glitch.  I'm beginning to believe that some of my intermittent extruder failures are due to the buildup of plastic dust in the hob gear, after which it starts to skip. But it's all so erratic.

Twice, suddenly the printer is making an enormous racket, and seems to be banging up against the stops; one time, it was in the upper left front corner, with the bed down at the bottom (?!?).

I assume that the belts are jumping, but when I move the carriage around by hand, it feels like there are no places where it catches.  The print is fairly simple, and it can go for 30 minutes without a problem, and then suddenly all hell breaks loose.

Not sure where to start with this one.  Seems very intermittent and unpredictable.

I long for a document that 1) recommends things to do prior to each print (lubrication, clean the hob gear, etc) and 2) has a symptom-vs-solution approach to all of the ills that our printers encounter. And I long for more predictability and reliability.

As for "what to do before you print" the answer is generally "nothing." For instance, here at Solidoodle we have printers for most of the office workers. I print about 10-15 objects per day, and do zero set up before each print. Just a little warm up. If your printer is properly set up, you shouldn't need to lube anything very often, and the gear should not be accumulating filament dust.

As for symptom vs. solution, feel free to suggest anything we did not include in the "troubleshooting" section of the website. I feel it is relatively complete, save for what I consider to be some "exotic" issues. Feel free to list some strange symptoms that you didn't know what to do with, and we will go from there.

I added a bit today. Maybe I'll try adding more in the future, I just don't want to enter wrong information by mistake. Also english is not my first language so I'm a bit self-conscious with those edits.

If you want to point me at your edits, I can review them for you, but what you've been writing on the forum seems spot-on to me!

That's what the wiki troubleshooting section is for but nobody is filling it out.

Well, over 1/2 of the content is mine, but that's not saying much.  We need someone to scour the postings and move relevant parts into the Wiki

Such a document would really be great! Especially the "these are my symptoms" -> "that's what could be the cause" part.

That's what the wiki troubleshooting section is for but nobody is filling it out.

Twice, suddenly the printer is making an enormous racket, and seems to be banging up against the stops; one time, it was in the upper left front corner, with the bed down at the bottom (?!?).

I assume that the belts are jumping, but when I move the carriage around by hand, it feels like there are no places where it catches.  The print is fairly simple, and it can go for 30 minutes without a problem, and then suddenly all hell breaks loose.

Not sure where to start with this one.  Seems very intermittent and unpredictable.

I long for a document that 1) recommends things to do prior to each print (lubrication, clean the hob gear, etc) and 2) has a symptom-vs-solution approach to all of the ills that our printers encounter. And I long for more predictability and reliability.