HP 19C carriage return

[Geoff Quickfall]

Okay, here we have a 19C, fully functional including the printer.

The problem is, the printer head will not park. It continually moves even when not printing.

I can physically place the head where it belongs at the far right in the parked position. This after a semi dissemble. The head remains in position but as soon as I hit print off it goes printing correctly then returning to the park position, bouncing off that and back to the left and then right and then...

it seems that it bounces off the parked position due to momentum and then ends up in past the park and off it goes.

under the printer the contact points work correctly opening and closing. it would seem that there is a brake function on return that is not functioning.

any ideas?


p.s. I have this ocurr on two machines that were working. could it be over voltage from 4 alkaline (6,0 volts) versus 4.8 volts NiCad. would it require a shotsky diode to reduce the voltage.

HP 19C challenged!

Geoff

here is the parked position for the head:



what are the trimming caps for (white pots)?



the whole damn thing apart looking for the fault!