Print Core 1 jammed UM3

[Whiteknuckle 1]

I cannot change Print Core 1, .25mm. I have followed the solution of lifting up on the nozzle while pinching the installation tabs. I even used needle nose pliers to squeeze the tabs together and pull. I am careful not to put enough force on it to bend the guide rods. My prints turn out good. The last time I changed this Core it was difficult but worked. Can the filament jam the Core so that it cannot retract enough to clear it? I don't see obvious build up of burned filament.

Thanks for the help...someone

jp

[myRobot 0]

I have had this problem recently where the print head will not come out. I ultimately end up breaking the "aluminum cooler" I think it is called. In the past my print heads have become so clumped with I filament I ordered 2 brand new print heads.