HP 19C carriage return

[ElectroDuende]

(09-09-2014 05:11 PM)Katie Wasserman Wrote:  Looking at Tony's hand drawn schematics it looks like there is a braking circuit, similar to the one described in the HP-97 service manual. Pin 10 on the PIK chip drives a single NPN transistor that shorts out the motor winding.

I bet for that. I've not worked on hp printers, but on other brands, and all of them have this braking circuit that shorts the motor winding to stop it in virtually no space. When this circuit (usually a single FET) fails, you have misalignment problems.