HP-97 Printer Malfunction

[ignazio]

Hi,
very strange behaviour. It's my opinion that you must check the home position switch too, disconnecting the two white/grey leads from the printer PCB and test the switch with an ohm-meter. When the head carriage is positioned near the right-hand wall , the ohm-meter should measure less than 1 Ohm and infinite when you rotatemanually the lead-screw away from the home position.
Test the cap connected in parallel to the motor leads too, and replace it if necessary.
Let me know the results of this check.