I have a reasonably old fullnut HP-41C. It was rattling a litle and I discoveed it had a broken post. However, on closer examination I find that there may be something else missing, and one more detail that I am curious about.
Here is the calculator. The red bits are the things I'm interested in:
The first thing are the connections to the display at the top left corner:
Note that one of these appears to be missing.
It looks like the solder joints are broken, bit the calculator appeared to work correctly. Is there normally a link here?
I've fixed a couple of calculators with really weird display faults that turned out to be a poor joint in these jumpers, but I can't remember if they had three or four links in this position.
If it is, then I am amazed that this calculator appeared not to have an obvious display fault. If it's not, then the pads sure do look like they've been used!
The other thing is:
Note that the two boards appear to be hels together by nuts on the lower posts.
Do all fullnuts have these nuts? I know that the older C's I've repaired do, but do they all?