HP-65 more on the card reader

[Geoff Quickfall]

I have checked my 65s and 67s.

Some of the keyboard PCAs are slightly warped as you indicate. All function correctly.

Could it be a trace microcrack once the board is flexed? Check the continuity of each trace with the board in place. Also check for cold solder joints on the gold prongs. These may be stressed with the flex.

Electronic noise may be introduced by your wiring at the foot of the board or are they removed prior to testing?

Geoff