A series of question, not really related to each other:
Can anyone tell me the years that the 7721A was made? It seems to be the 80's but it would help to know the actual range of years. Is there anyway to tell from the ID/serial number what exact year it was manufactured? I even found a very in depth article about the history of Matsushita/Panasonic company, almost year by year of what they did/made, but there isn't any mention that they ever even MADE test equipment.
I can't find anything technical about this Panasonic analyzer online except 2 versions of the same manual one numbered 2, and one numbered a vers 3, and they are too general for the troubleshooting I need to do. (under certain circumstances, the two meter needles will peg out at maximum and will not unlock themselves. I have refloated many solder joints and replaced a lot of old electrolytics (some were leaking). Touching the white band of wires inside though will break the lock, the relays will click again, and the needle comes back to where it should be. But where i need to press on those wires changes, so it's not a consistent point.