Restore Casio ALT 6200

The Casio alt 6200 is one of the classic casio models, which you either find horrifying or love. I discovered it in a forum post about watches where you can see it in pictures. And if you have this model you can download the scanned manual.

To me, personally it seems a very successful design, I like almost more than the Casio alt 6000. And when I saw it in a second-hand website at a great price, do not hesitate to buy it.

Initial assessment

In principle, as I received the Casio alt 6200, I was surprised by one thing: its exceptional condition. Actually, it seems to us. The glass is unpolluted, the bezel and the case are unmarked and in a good, new condition.

The alarm is working, the buttons are not hard, and the bathymetry and altimeter are also working properly. Actually, it was a good buy.

As I knew, the main problem was the display. On the top, where the barometer graph is included or shows the English name of the day of the week, some points were missing.

This error is typical of a bad contact of the zebra connectors with the screen, so we started, since in principle, it should be a simple task (although an unexpected problem will arise).

We began dismantling the Casio alt 6200

Typically, we start unscrewing the back cover and look inside the box.

When we access, we see that it even has the plastic gown to hold the module inside the box. And a lot of fingerprints on the module.

We will release the battery to disconnect the sensor cable and take the module out of the box. And here's the problem...

An unexpected problem

The problem is that the screw is over threaded, no matter how many turns it makes, it does not unscrew. I try several ways and there's no way to loosen it.

Also, this screw is a problem, since the structure of the module is a sandwich where the lower layer is the plastic piece of the screen; in the middle is the circuit of the module and in the upper part the plastic piece that houses the pile.

The screw that gives problems, holds the metal cover of the pile, crossing the sandwich of the clock module, so the access to the back of the screen is not possible.

Accessing this part would be ideal, as it is much more comfortable to check the state of the zebra connector and how to place it correctly so that it makes contact with the screen and the data is displayed without problems.

Be careful with the sensor

To avoid problems with the sensor, I loosen the metal case that holds the battery (partially, since the screw prevents me from loosening it completely). I take out the battery, a quality maxell cr2025 and check its charge. As it is correct, I choose to leave it, there is no need to change it.

Now let's go to one of the most sensitive parts of the protek watches, the barometric sensor. Any damage in the flex connector or trying to disassemble the sensor itself, will cause its failure, so we will lose the height and barometric pressure values of the watch.

With great care, I remove the board that fixes the connector to the circuit and I take the module out of the box to be able to manipulate it more comfortably.

The problem, as you can see in the next picture, is the typical of the Casio alt 6000 and Casio alt 6200 models. Due to the design of the module, the plastic piece does not completely surround the zebra connector, along with a small bulge makes it bend and ends up losing contact with the connector area of the screen.

As I did in the Casio alt6000 (restoration pending to be published), I will try with a small piece of cardboard to "straighten" the zebra connector to improve the contact with the screen.

Although the method is not at all professional, I cut a couple of small pieces of cardboard similar to the zebra connectors and proceed to place it on the back of the zebra connector. This way, the connector is straightened and the contact with the screen is improved.

Checking if the repair works

Now all that's left is to perform the reverse steps. Tighten the two screws on the metal display holder. Replace the battery.

And clean the inside of the box, which is always full of dust, if like the plastic mask. That once everything is assembled always remains a speck around and can not stop seeing it. It makes me so angry...

We put the module inside the box and, an important step, we reset the module. We connect the connector marked "ac" with the upper part of the battery holder (+). And bingo, it works!

As you can see, the day of the week already looks perfect, we can say that the operation has been a success.

To avoid problems with the sensor, I remove the battery again and screw the flex connector of the sensor to the circuit of the module. We reconnect the battery and do a reset. We check that the altimeter and barometer are working properly.

If we choose not to remove the battery to screw in the sensor's flex connector (I do not recommend it), once screwed in, we must do a reset even if we have not removed the battery. Otherwise, an "error" will be shown on the display when accessing the barometer and/or altimeter.

We check that the buttons work properly and the sound also with the back cover on. We screw the cover on and that's it, we're done.

As it came without a strap, I took the opportunity to put a two-piece canvas, since the design of the handles allows to put a canvas without problems. This is how my "new" Casio alt 6200 looks like for now: