I am new to 3D printing and have been working to introduce 3D Printing to my high school class. We’ve had a luzlbot mini for almost a year and have had no issues. We have been printing nametags (images included, they are about 100mm x 70mm x 8mm made in TinkerCAD, in the one image you can see one of the older printed name tags and how they should look) and have not had any issues, until about a week ago. The prints started having issues (I have included some images). Basically, the print starts and then either has the not completely melting issue, or the first layers print and then nothing. The one fan is on all the time and the second fan does come on as it goes through the print. I am able to set the temperature and extrude, and the filament comes out in a nice straight string (sorry if not using the proper terminology). We use PLA filament (bought from lulzbot). I have changed the filament and still having issues. I do notice with the prints that start to print and then do not finish, when I take the filament out, there is sometimes a gouge in the filament and some fine shavings around the area. I did try printing a small little christmas type hook, and it seemed to print ok.
Any places to look for troubleshooting tips would be wonderful as we are all complete newbies.