1LM2-0002: HP-41C/CV/CX HalfNut System on a Chip specifications?

[Paul Berger (Canada)]

Here are some notes I made when working on halfnuts, there is really not much to see in both cases the ROMs are hybrids with the dies wire bonded directly to a substrate and encapsulated in epoxy. The hybrid containing the CX clock and other functions is mounted on posts above the processor chip, the holes for these posts are also present in the CV version. there are 6 holes near each edge of the main board opposite the processor.


  Halfnut.pdf (Size: 12.6 KB / Downloads: 94)

Other than the description of the diagnostic tests the coconut service guide is not much use. The way the halfnut is built I suspect the service guide was "Verified not functioning? if yes pitch in bin and send customer replacement"

Paul.