Homebrew PCBs

Yeah, I think you are on the right track there - it is a timing 
issue of some sort I think.  I don't think it has to do with the 
leading edge detector though.  I don't recall this printer every 
picking up a piece of paper and having it ready to print during 
power up.  Rather, the only time paper is picked up is when it is 
suppose to print something.

It has to be something silly with that other sensor on the feeder.  
I will have to watch the gear train to see what it is doing and try 
to "open/close" the switch in sequence to that gearing and see if 
that helps.




>   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
>