HP97 The journey begins

[teenix]

(01-11-2019 04:06 AM)Paul Berger (Canada) Wrote:  Does the printer try to do anything? With no paper in it pressing the paper feed button should cause the print head to move left about 1/3 of its travel, this is of course assuming that the wires or the button have not broken odd their connectors. if they are not connected correctly the printer will not work properly either. I had one with a marginal PIK that when cold the printhead would barely get off the right margin, but after it was on for a while it would print normally.

You will find lots of tutorials for the card reader, the trick to getting out the cable without damaging it is to slip a piece of stiff plastic in between the contacts and the cable, I use pieces cut from blister packs.

Paul.

Thanks Paul,

The first CPU board made the card reader and printer do weird things, but none of that with the second board. The printer carriage seems to have tight spots as I manually but carefully wind it along the worm drive. It is all full of gunk so I have stripped it down to give it a clean and a bit of lube. The motor was trying to drive it but it too slowed down as it travelled left.

I did manage to get the ribbon cable out after I figured out what was required. I used some folded aluminium from a soft drink can which is nice a smooth. It appears that the thickness of the "tool" is important. Too thin and the cable comes out but the tool gets stuck in and another tool is required. If the thickness is right then it will raise the rear of the connectors away from cable by pushing up on their leading edges. Then, if you make sure you don't push it in too far, the cable slips right out.

I'll have a good read of the service manual for the printer.

When it is reassembled, I will try out what you mentioned. It is interesting that it moves that far before figuring out there is no paper. The magnetic carriage return switch must keep the reed switch shorted for a bit of the initial carriage travel. I haven't figured out how the paper out mechanism works, it looks like 2 wires that go to 2 metallic plates that are close to or rub up against the paper.

cheers

Tony