Recently purchased a nice HP.45 calculator on the Unmentionable Site.
The only issue is that no keys on the bottom row register when pressed.
Disassembled unit, and found no issue by visual inspection (broken trace etc.)
All LED segments light up OK.
It appears either the bottom row is not getting "strobed", or the return from that row has an issue (either electronic or mechanical).
Any ideas would be appreciated.
Thanks.
John Stark