Homebrew PCBs

lcdpublishing wrote:

>There is one thing I have to remove and this too could be the 
>problem.  The paper feeder has an opto sensor on it to detect the 
>position of a shaft (the one that holds the cams to feed the paper 
>in).  This sensor is NOT the paper "leading edge" sensor.  I have 
>tried to manual rotate that shaft so the sensor can "see" through 
>the hole and so that it is blocked - same errors either way.
>  
>

  The paper edge sensor may be expected to go active after a certain 
time from the paper pick up sensor.  The paper pick up roller picks up, 
paper curls around, then the paper edge/present sensor goes active.  If 
you don't get it around the time the printer expects after the first 
sensor, the printer may give an error, seeing that it didn't really pick 
up a piece of paper when it thought it did..  IOW in some printers these 
sensors aren't independent and just for their job, it is expecting a 
certain chain of events with pretty specific timing along the paper path 
or gives a feed error or similar.  So you may have to move the pick up 
roller or fake the signal back along the straight path far enough to 
have the right timing.

Alan