Restoring HP-65

[albertofenini]

Hi everyone,

firs of all let me introduce my partner in all these activities,
he is of great support, optimistic and of great help in this work,
let me introduce you Edoardo, my 11 years old son and probably one of the youngest calcs and
led watches collector.

Here we are working at our HP-65 restoring project, we will dea later with the card readers.
Following a old procedure found on the Forum we have better organized our work,
borrowed a working HP-65 working mother board from our collection and mounted the
keyboards pcb as shown.

So far we have managed to bring back to life a keyboard/led pcb from the broken units,
by cleaning with a strip of sandpaper (2000 grit) all the keys plates.

You will see in the pics is called Keyboard 001 and shows full array of 8.

Then we did the same with KBD002, but with no results.

Also, we had a third Keyboard PCB, we can't recall wher it was coming from, that was
with out LED modules. So we recovered the modules from an HP80, but also this had
some issues.

We had then some donors, like HP80 and HP45 and we recovered from those the
Anode Driver 1820-1029 (HP80 and HP45 use the same chipset the HP-65 does) and the
Cathode Driver (the HP45 uses the same that the HP-65 does) however, we also don't know
if those were working previously or not, and the results are not so good.

We are now thinking of soldering two 20 pins sockets on a Keyboard in order try different
combination with the hope to find at least a good couple of chipset so to bring back to life
a second keyboard PCB.

Does anyone know what kind of measures can we take to understand if those chipset are working ?

Then we also tried to recover the CPU board we have cleaned last time, but we no progress.
The only thing we noted is that some of numeric keys work (3,6 and 9) and that Enter works,
and the - and + keys work, so that we have been able to perform simple operations.
This makes me think that the Hybrid is at least partially working, am I right ?

We are thinking to by a USB oscilloscope and connected to a laptop, this could be a good improvement in our lab and could help us in make more efficient diagnosis.

Take care everyone, and if anyone wants to add any idea, please let us know

Alberto & Edoardo