Thanks!
I don't think that many prototypes like this one is left in the wild, so it
would be nice if anyone had a schematics diagram of the calculator part or
datasheets on the ic's used.
Since the voltages rise well beyond 2-3 times the rated voltages I think
the poor design of the power
Thank you Martin for the detailed report! I wonder how many of those
machines are still around, just in case a fully working calculator can be
put together from parts. But probably the display is the toughest component
in there!
Maybe the damage was caused by a lightning strike, at least I
Well, the ZM1200 Pandicon is working as it should on all digits, but the
calculator itself isn't, it is almost completely dead. There are only four
signals from the main board to the Pandicon board that shows any life
whatsoever, a pity now that the power supply works.
The power supply is not
I got it up and running!
I just replaced Q6 which someone had replaced with a BC327-25, but looking
at the circuit diagram I couldn't understand how a PNP transistor could
work there so I replaced it with a BC547B as I didn't have any BC337 which
was used in the other position.
I also
I've already seen that a lot doesn't make sense, some transistors, the SCR
and UJT have all been connected in the wrong way compared to their
datasheets and how they are soldered on the circuit board plus one trace
has been cut which is necessary to power it all up. So, now I have a lot to
do
Yes of course I will share what happens.
I am right now reverse engineering the power supply but since I don't know
what the original transistors where, they've all been replaced with modern
components, and I am not even sure the replacements are the correct types I
don't know where I will end
Hello Martin.
No, I don't have the diagram. I have seen that calculator for sale and I
was tempted to get it ... almost just to try to fix the power supply! At
least I think it is the same machine. Would you share your findings,
if/when you get it back in working state?
I have a Casio CL-200 with
Hi,
I just bought an old SCM Marchant 414 with a 14 digit ZM1200 Pandicon as
the display element!
The Pandicon contains Neon and looks just fine however the previous owner
had disconnected the power supply from the main board and the power supply
has been repaired extensively.
All of the
