Another HP-67 repair query

[coitboy2000]

(10-24-2020 12:28 PM)teenix Wrote:  

(10-24-2020 11:26 AM)coitboy2000 Wrote:  Probably what the 2n2222a made no difference. Will a 2N3906 be ok?

Cheers

Richard

You can only try, the device I used has similar characteristics.

cheers

Tony

What is the compatibility like between the HP-45 and HP-67 ? I have a HP-45 with a working display. Anode, Cathode and LED's ? Different part numbers I notice. I have re-soldered pretty much everything on the calculator and I still have no display. The RCD signal seems fine. Is there a way to check for shorts on the keyboard ?

I may purchase a new board to try in the meantime

Regards

Richard