Issue with filament while printing

[sriccio]

Having an issue and hoping for some help... I recently replaced the following on my Makerbot Replicator2: Heater block assembly, thermocouple, and the heater cartridge. I have made some really nice prints since the replacement but a couple of days ago i started to have a few issues. The filament would just stop. It didn't break and I would unload the filament and it looks like the attached image??Before I take the whole assembly apart I am looking for an answer - is it the temp that i am running (usually 220 to 230) or is the assembly itself? Thanks in advance for all answers.