Restoring HP-65

[albertofenini]

Dear All here we are !
Happy New Year everyone !!

We installed the software and started to use the Scope.
It is absolutely the tool that makes possible repair this stuff.

We worked on both the keyboards and the CPU boards and we have got so far two units working.
On one CPU board we discovered that the CR CK signal were not handled and you will see why in
the next pictures. We then de-soldered the Hybrid and replaced with a spare one. This was from a
old project where the board had some PSU issues but the CPU was eventually working.

We also fixed another CPU board that had probably a PSU issue replacing the diodes and a
capacitor that we took out from a donor. We also stripped all the components and re-soldered on a different PCB.

With the scope we have been able to investigate about anode and cathode drivers on the two
keyboards that were not working properly. Both had the ICs non working and we soldered a
DIP socket, so that we could test all the spares that we had from two old HP45 that share the
Anode and Cathode drivers. We have found out only a working couple so that now one of the
keyboards is also working.

Next step will be reassembling these two units and start repairing their card readers.

What's left :
A bare HP65 CPU PCB
Enough components to rebuild it, although one of the ram modules could be faulty has it had a note saying "faulty"
What's missing :
a good couple of anode and cathode drivers
a good hybrid
If you look at the pictures you will notice that we have two hybrids left.
These are "first generation" and the pins are physically connected to the ceramic and
then a gold strip connects the pin to the internal modules.
Later versions are more robust and pins come out from underneath.

One of these two is in unknown working conditions, since it was given to me from a collector
many years ago, but I can't recall if it was working or not, also has some broken pins.
The second one, is logically working since it was able to perform math, but has a lot of missing
pins, and what's worst the gold strips coming out of the hybrid are too short.
This is the one that was not addressing many rows and columns exactly because of this problem,
We have collected all of the missing pins, so we have those, but has anyone ever succeeded in
re-connecting these ? How could we get those short strips of gold soldered with the pins ?
Any idea or suggestion is welcome.

Also, if some one has spares to share or willing to trade them for something else please let us know.

We will keep you posted on the card reader in the next days

Take care and thanks to all of you that has provided suggestions or hints

Edo & Alberto