Hi Check all cables near and going to the position sensor and carriage motor. As the main board is on the back of the door any thing that moves when the door is opened is also suspect. Also inspect PCB's for cracks. The constant impacts when printing would cause all of the usual vibration related problems. Heads suffered from fibers from the ribbon getting up the pin holes in the synthetic agate. Dump the head in a jar of absolute alcohol for a week. Change liquid if particles seen. Rod Smallwood (ex Digital Terminals Product Line 1975-1981) -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Gordon JC Pearce Sent: 24 January 2006 20:22 To: cctalk at classiccmp.org Subject: Jittery LA36 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. Gordon.