Reproduce the problem. Try to make it happen again under the same circumstances and observe it closely. Try to collect as much information as possible just by watching.
Identify the problem. With the information in the last step, try to find a specific, short way of describing the problem. That will help you with forum searches, Google searches, or just as a way to continue through this list. Is filament not extruding? Are your models warping? Is the software crashing? Is your filament not sticking? Is your print head not moving?
Isolate the problem. This is where you get to be an engineer. Step through the process in your mind and address each part one at a time. My first major problem was that my plastic was not extruding so I had to test the individual components that make the plastic move:
- The filament is pushed by a stepper motor. Is the stepper motor spinning? Test it all by itself with no filament.
- The stepper turns a hobbed bolt which causes friction on the filament. Is the hobbed bolt clean of plastic debris and does it spin freely?
- The filament is held in place with tension on the idler. Does everything line up there? Does filament move when you turn it back and forth with your hand?
- The filament must melt to the right temperature before being extruded. Is your software set to the right temperature? Can you measure it with an IR thermometer?
- The melted filament must go through the nozzle. Is any filament at all going through? If you remove the nozzle tip and tell it to extrude, does melted plastic come out the bottom?
How to be a BETTER engineer: Learn about all the things your 3D printer does. There are no mysterious elements to Printrbots: every part is well understood by the community. Learn all about the combination of events that make a 3D print: movement, heat, bed adhesion, filament, and design. Learn about the combination all those elements: Bed adhesion is a combination of heat, bed texture/smoothness, model footprint, and sometimes add-ons like blue painter's tape or hairspray.
Final thought: You have US! With all the Printrbots out there, chances are your problem is not totally new and unique. The community has probably seen it before, figured it out, and fixed it. If you can't get as far as fixing the problem yourself, just collect all the information you have and search the forum. If you have no luck there, write a post being as specific and detailed as possible and post all the steps you took to troubleshoot the issue. Once you fix it, come back to the forum and tell us what worked: you'll be helping the next person who has the same problem.