HP-65 missing all "g" segments

[albertofenini]

Hi everyone,

we need a bit of help with this one as well ...
works fine but what shown on the picture should be a full 888888888 display
i.e all the "g" segments are missing.
We think it could be a faulty Anode Driver 1820-1029 and possibly the 11th pin
which should drive the g segment, but any advice or suggestion about what
to measure and what to expect is welcome !!
thanks in advance !!

Pictures : HP-65 missing all "g" segments

[teenix]

(06-25-2020 10:05 PM)albertofenini Wrote:  Hi everyone,

we need a bit of help with this one as well ...
works fine but what shown on the picture should be a full 888888888 display
i.e all the "g" segments are missing.
We think it could be a faulty Anode Driver 1820-1029 and possibly the 11th pin
which should drive the g segment, but any advice or suggestion about what
to measure and what to expect is welcome !!
thanks in advance !!

Pictures : HP-65 missing all "g" segments

Hi Alberto,

I'd say, you've probably nailed the problem, pcb track, solder connection etc.

cheers

Tony

[albertofenini]

Hi Tony
Are those segments joined by a single pcb trace ?
Does anyone have a schematic other than Tony Dwell’s
One that allow to see traces and connections ?
Thanks for your reply !

[teenix]

(06-26-2020 06:07 AM)albertofenini Wrote:  Hi Tony
Are those segments joined by a single pcb trace ?
Does anyone have a schematic other than Tony Dwell’s
One that allow to see traces and connections ?
Thanks for your reply !

Yes, they should be.

I don't have PCB trace or connection diagrams, but I have some cleaner schematics at...

http://www.teenix.org/classSchm.zip

cheers

Tony

[albertofenini]

Thank you very much !!