The Casiotron S-21 is the watch I consider the coolest out of my entire collection.
I fell in love with it at first sight and bought it about six months ago, but the negative battery contact had completely broken off due to corrosion.
So I cut a piece of phosphor bronze sheet, made a new negative contact, and soldered it into place. I managed to get the watch running, but some segments of the LCD were missing. I couldn’t figure out the cause, so I put it aside for a while.
Then, as I finally reached the point of organizing the grail pieces in my collection, I decided to work on restoring it again.
I cleaned the zebra strips and tried a few things, but nothing fixed it. I couldn’t think of any other cause besides the negative battery contact, so I took a closer look.
That’s when I remembered GPT telling me that uneven pressure on the zebra strips can cause missing segments on an LCD.
Could the raised solder joint where I had attached the negative contact be affecting the internal connections?
With that in mind, I filed down the soldered area to make it as flat as possible.
And then, amazingly, every segment of the LCD displayed perfectly!
It seems that the height of the soldered area had been affecting the internal connections.
I was incredibly happy!
I’d been looking forward to the day I could show off my S-21 on Reddit, and if I was going to show off such a cool watch face, I wanted to restore it to perfect condition first.
No matter how many times I look at it, I still can’t stop getting excited.
The S-21 case is crafted with almost obsessive attention to detail. It truly has the presence of a true masterpiece!
1. Perfect Composition of “Light and Shadow”
This isn’t just an octagonal case.
The flat surfaces on the front and the lugs feature vertical brushing that boldly emphasizes the texture of the metal.
On the other hand, the sharply cut edges have a mirror-polished finish.
The coexistence of these two finishes makes the entire case look incredibly three-dimensional and shine sharply when light hits it.
The sharpness of these edges is filled with the pride and craftsmanship of the artisans of that era.
It truly is the Lotus Esprit Series 1 of the CASIO watch world.
It feels as if Giorgetto Giugiaro himself had been commissioned to design it.
Of course, it was actually Seiko, not CASIO, that collaborated with Giugiaro (on models like the Macchina Sportiva and Speedmaster), though…
2. The Irresistible Sense of Solidity of the Integrated Lugs
The design of the lugs flowing seamlessly from the case is also amazing.
It has an overwhelming sense of mass and strength, as if it had been carved from a solid block of stainless steel, something that seems impossible to achieve with thin stamped metal.
3. The Incredible Unity Between the Case and the Dial
And finally, the multiple silver lines printed on the black crystal.
They perfectly echo the octagonal shape of the case and naturally draw your eyes toward the center.
From the rugged stainless-steel case to the delicate heartbeat of the LCD.
Everything converges beautifully.
Overview
Model: Casiotron S-21
Module: 17
Year: 1976
Material: Stainless Steel
Factory: JAPAN C
Functions
Time and seconds display
Stopwatch
Timer
Calendar
Light
