Thanks Katie!

[Katie Wasserman]

This was 13 years ago, so my memory of the repair is a little fuzzy. However I think that the idea of limiting the current into the sync pin occurred to me becasue the calculator failed at low temperatures, meaning that probably more current was flowing. I experimented with a few different current limited resistor values and found that 20K worked! As I recall many other values worked too, but this was in the middle of the range.

Over the years several people reported that this fix worked for them -- although it doens't always work -- I'm glad that you found it useful too.