That error code generally means that the print head has over heated. This could be caused when the print head is changed. A ribbon cable connected into the print head may have damaged fingers.
If the print head is starved for ink, and is firing "blanks", it will cause this condition.
It is usually not generated out of the blue by itself, but happens when another
incident precedes it, usually changing a print head.
If it persists, double check the ribbon cables to the print head (if it was indeed changed),
the ribbon cables you see when you lift up the top cover in the front of the machine
(there are 6, unseat and reseat them all).
Error Code 1001B Help 
Re: Error Code 1001B Help 
