Restoring HP-65

[albertofenini]

Hello Max,
we wrote in the past, so it's nice to hear from you again, thanks for your reply.

Let's say that we have a working unit, and two units under restoration, these tow units are complete with keys, keyboard and power connection that we will call KBD001 and KBD002.
At the moment, other than the working CPU, I only have one CPU board under restoration , CPU S/N APD 1540 T.

This is what I experience so far :

PROBLEM 1 : If I put the CPU under restoration I didn't have the control of the last two rows of keys. This can't be because of a bad keyboard, since the unit housing the CPU is the working one.
So I re-passed the soldering points of the hybrid on the side that control the keyboard rows (I do have the schematics), and it has got worse, since now most of the keys are not responding

[attachment=6635]

Then I did the opposite : I have put the working CPU in the cases with KBD001 and KBD002. Both appear in very good conditions as you can see from the pictures, and in this test the CPU board is working since is coming from the working unit.
KBD001 as a weak metal plate, you don't hear the classic click when a key is pressed, kind of stressed metal. But if all the keys are pressed strong enough they work.


PROBLEM 2 : when the working CPU is put in the case with KBD002, on few led lights on ,as you will see in the picture.


[attachment=6636]
[attachment=6637]
[attachment=6638]

What can I do to solve PROBLEM1 and PROBLEM2 ?
Thanks in advance, Alberto & Edoardo