Printing problems

Hi, can anybody tell me why my prints have gone from the good one to the others, same filament, just a day apart:
the 2 white prints done on same day good one first then the other, should be identical: s923.photobucket.com/user/deafol … sort=3&o=0

Hi, it appears to be a blocked hot end, i have burnt out the blocked filament, tried to print again but the same thing happened, what can I do to prevent this happening

The first filament is white, the second is black? So, not quite the same filament. I have experienced issues with differently colored filament and needed to increase the temperature by 10°C.

Hi, there are 2 items printed in white, one good one bad, there are 2 items printed in black one good one bad, ones in white same filament, the ones in black the same filament