|Voyager LCD variations|
Message #5 Posted by Randy Sloyer on 18 Nov 2003, 8:25 p.m.,
in response to message #4 by Nelson M. Sicuro (Brazil)
You are correct: The entire Voyager line (10/11/12/15/16) used the same displays, but not always at the same time. So, I would like to add the statement: "Most of the time". This is especially true as you found out with later model 12C's. They where always the first to change methods, the 11 and 15's followed. I've started to track the versions and serial numbers, but I don't have enough data yet for it to be useful.
I must disagree with you about the easiest version to find. It has been my experience that the older the unit, the harder it is to find a display for it. Volumes did not start to build for a few years after introduction so there are fewer old units. I'll bet there are 1000 new 12C's out there for every single older USA unit.
I have been able to identify three different versions with two being somewhat compatible. I refer to them as "fine pitch" and "coarse pitch".
The earliest version is the unit with separate keyboard and logic board parts. These can be identified by the springs in the battery compartment - straight contacts on either side, no spring. These are the hardest to find and to work with. The LCD is a "fine pitch" version that is held in place with the metal frame. It is positioned poorly by the frame.
I think due to the cost of manufacture, they re-engineered the unit to be one circuit board. This is where the coil spring on the left side of the battery box appeared for the first time. The same "fine pitch" display was used, but it was mounted by means of two-sided tape to an intermediate plastic carrier. The carrier had two indexing pins which made the job of properly aligning LCD as we say, "A piece of cake". Now that the LCD sat further away from the circuit board, the zebra connection strips got longer.
At this point, I would like to say that these two "fine pitch" versions are compatible. If you have a fine pitch LCD on a carrier and need one without, a little UN-DU (heptane) will pop it off for you. The same is true in opposite, if you need one with a carrier, you'll have it on the broken one, just remove the broken one and stick the carrier-less one back on. Just examine the LCD position on the carrier before removing, it will match up in the Y direction, you'll just need to center it in X. Use the proper length zebras.
Somewhere around date code 28 (1988), they redesigned the circuit board (again) and changed the spacing and width of the connections on the LCD. I suspect the desire was to ease alignment problems in assembly. These are what I refer to as the "coarse pitch" version. This one is VERY easy to find, just get a throw-away Chinese 12C and you're set. Yes, the LCD version used in the 3 volt units works just fine. I have only seen 11, 12 and 15C's with this version. These are VERY easy to change out and almost never have missing segments since the pads are so much larger, a drop to the floor will not cause misalignment.
I believe the 10C was only built in the two board version but I have not been able to verify. I know the 16C was built in both (I own 2 as I was a software geek first) but never made it to a coarse pitch version as it died a premature death.
Hope that helps.