What are you sending to the printer ?
How do you have the laser printer configured ?
I assume it is attached to LPT1 if you are using lprint
(or perhaps com1).
Generally you will need to set the printer to Raw.
If it has the option for dos capture then enable that and try it.
If you are sending escape sequenses or dumping qb4.x or above code, is the code saved in Quick-mode ? If so, save it
as ascii text then redump it.