Jittery LA36

[Tony Duell]

> 
> Hi there,
>    I've finally got the ribbons for my LA36, unjammed the pins in the 
> printhead and it is printing.  It's not quite right yet, though...
> 
> The printhead often jitters backwards and forwards, sometimes several 
> inches.  When you hit "RETURN" it's obviously lost track of where the 
> head is, and slams it into the left-hand stop, where it sits obstinately 
>   pressed against the spring.
> 
> Cleaning up the photosensor bit on the interrupter wheel seemed to help 
> a little.

I thinkl you're in the right area. I would grab the prints and look at 
that circuitry, stick a 'scope on the outputs of the phototransistor 
amplifiers, etc.

Oh, and do check the power lines for mains ripple!

-tony