DeanSEES

Hi, I'm new to 3D printing and I'm struggling to complete some pretty basic jobs. I printed some sample holders (10 of them) in about 5 hours which went well yesterday. I did an overnight print for a pipette holder but it only got halfway through, the printer head was still moving but no plastic was being ejected. I aborted the print and went to clean the nozzle for any blockages using a cold pull method. I've tried to reprint the sample holders today after cleaning the nozzle but the plastic is not ejecting. Has anyone got any advice for this please? Bear in mind I'm new (and a little frustrated!) so advice needs to be idiot proof! Secondly, the sample holders have a brim around them which appeared yesterday on print preview mode in ultimaker cura but now that brim is not appearing around my models anymore. Whenever I change the brim settings it just seems to show a border around the build plate not my models. Any help would be greatly appreciated, these sample holders are important for an upcoming experiment. Thanks