Makerbot Replicator 2 cant print for some odd reason

[Feliks87]

I had a similar problem with my Replicator 2X...

the reason the feeding failed was the fact that my spools couldn't "roll" smooth enough to give enough filament to the extruder and the feeding motor shredded the filament while trying to pull it off the spool
that was because I use 1kg spools which are too large for the backside mounted filament holders which resulted in unsmooth "rolling"

there is also the problem of heat... due to the hood of the Rep2X a lot of the hot air vents to the backside and onto the spools which preheats the filament a lot during longer prints making it weak and stretchy.. another reason why I moved the spools from the backside to a place somewhere else to prevent the filament from preheating (see here)

I also printed without the hood and it still gets quit hot on the backside so mayber you have a similar problem