Disassembly of HP-19C

[Don Williams]

Taking the calc apart is not the challenge. It is the reassembly that is the problem.

If I remember correctly there are two boards and two rows of contact pins between these boards. One row near the top of the boards and one near the bottom. When you have to reassemble the calc you will find it very difficult to determine if those boards are actually aligned. You cannot see all the pins when you attempt to mate the boards.The tips of these pins are easily damaged if things are not perfect. If you damage a pin good luck in finding a replacement. Even if you did have a replacement you then need to solder it in as perfectly as the other pins (which were machine aligned and soldered perfectly} before it will mate with the other board.

HP must have had some kind of assembly jig or tool on the production line to aid in the this task.

The first time I reassembled one it went as smooth as glass. Just luck though. That never happened again. All subsequent attempts resulted in broken pins.

Your experience may be different. Good luck.