Casio CGW-50 (Cosmo Phase) – Restoration

I bought this Casio CGW-50 “Cosmo Phase” on eBay. The price was surprisingly low for such a rare model, even considering its bad condition. When I saw it, I knew it was risky. But with my tools, patience, and some luck, there was a good chance to bring it back to life.

The CGW-50 is not a common watch. It’s part of Casio’s short-lived “Cosmo Phase” line, built around moon-phase tracking and futuristic 90s styling. These watches almost never show up for sale, and when they do, they’re usually expensive or broken.

When the package arrived, I could already see trouble. The watch was in terrible shape: deep scratches, missing parts, one broken lug, and it didn’t power on at all. For many people, it would be a parts watch. For me, it was a challenge I couldn’t ignore.

What Was the Condition of the Watch at the Start?

When I opened the package, I immediately understood why the price was low. The CGW-50 looked like it had been forgotten for decades.

The case was full of deep scratches, and the acrylic crystal was cloudy and dull. The back cover was completely missing, and one lug — the small arm that holds the strap — was broken off. The watch didn’t react at all when I tried to power it on.

I inserted a fresh battery and did an AC reset, but nothing happened. Total silence. No display, no beep, nothing.

At that point, I already knew it would need a full teardown. The inside probably suffered from battery leakage or corrosion. These old modules are sensitive, and even a bit of acid or moisture can block the LCD or kill the circuit.

Finding parts for the CGW-50 is almost impossible. It shares some components with the TGW-10, but original parts rarely appear online. Still, I decided to go all in — to clean, rebuild, and see how far I could push this restoration.

This was going to be one of those projects where patience and creativity matter more than spare parts. 😅

Restoration Process – Step by Step

1. Disassembly and Cleaning

The first step was to open the case and carefully remove the module. I took everything apart — LCD, PCB, metal cage, and rubber contacts.

Each part was cleaned with isopropyl alcohol (IPA) to remove dirt, oxidation, and battery residue. I used a soft brush for the board and cotton swabs for the LCD contacts and conductive rubbers. After cleaning, the board looked fresh, but the module still didn’t power on. That meant the problem was deeper — maybe the LCD itself was damaged.

2. LCD Repair and Polarizer Replacement

The LCD was in bad shape. The old polarizing film had turned yellow and uneven, so I peeled it off and applied a new polarizer sheet.

This usually helps when the display looks too dark or has poor contrast. After replacement, the digits became visible again, but with one problem — large gray and black stains remained on the screen.
Those spots were permanent acid damage caused by an old leaked battery. Unfortunately, that’s something you can’t repair. Still, the module was now alive and functional, which was a big win. 🔋

3. Parts Swap from TGW-10 Donor

The CGW-50 and TGW-10 share a similar internal design, so I used a TGW-10 as a donor watch.
I took the plastic module frame and metal cage from it — both were in good shape and fit perfectly.

This helped to stabilize the whole module and secure the LCD inside. After reassembly, the watch finally booted and worked correctly. Seeing that “Casio” logo appear again was the best moment of the day. 😄

4. Case and Crystal Restoration

Next, I focused on the case and crystal.
I started by wet-sanding both surfaces with fine-grit sandpaper to remove deep scratches. Then I polished the acrylic crystal until it became clear and shiny again.

For the resin case, I used a Mr. Clean magic sponge to restore the matte factory texture. This step gave it that original Casio look — smooth, but not glossy.

5. Rebuilding the Broken Lug

One lug was completely missing, so I had to rebuild it from scratch. I used super glue mixed with baking soda, which creates a hard, sandable material. After shaping and smoothing it with a file, the lug looked solid and almost original. It’s a simple trick that works great for small resin repairs. 🛠️

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6. Final Assembly

With all parts ready, I installed a 14 mm replacement strap — not original, but similar in shape and style. Since the original back cover was gone, I used one from the TGW-10 donor. It fit perfectly and sealed the case properly. Before closing it, I added a bit of silicone grease to the gaskets for better protection. Then everything went back together. The watch powered on instantly and started running again.

Result – How the CGW-50 Turned Out

After everything was done, the Casio CGW-50 Cosmo Phase finally came back to life.
The module works perfectly. All functions respond well, the sound is clean, and the buttons feel smooth. The LCD still has some gray stains from the old battery damage, but the digits are visible and sharp enough for daily use.

Visually, the watch looks a hundred times better. The case is clean and matte again, the crystal is polished and clear, and the repaired lug holds strong. With the replacement strap and TGW-10 back cover, the watch feels complete and wearable.

Sure, it’s not a museum piece but it’s alive, functional, and ready to be enjoyed again. That’s what matters most to me. Many people would have thrown it away, but now it’s a working piece of Casio history.

Restoring this watch reminded me why I love this hobby. Every rescue has its story. Some are easy, some take hours of trial and error. This one was difficult, but the result was worth it.

The CGW-50 is one of the rarest Casio models I’ve ever worked on. Seeing it ticking again after decades of silence feels great. Another small victory for vintage Casio fans. 🔧⌚

Final Thoughts

Saving watches like this keeps the history of Casio’s creativity alive. The 80s and 90s were full of experiments — pulse sensors, moon graphs, remote controls — and every model had its own story. The Cosmo Phase line is part of that era, and I’m happy I could save one of its last survivors.

If you’ve ever found an old Casio that looks beyond repair, don’t give up too fast. Many of them can still be brought back with some patience, cleaning, and imagination.

Got a broken Casio you want to save?

I also restore watches for collectors and fans — from simple cleaning to full rebuilds. If you have a classic Casio that deserves another chance, you can contact me through my Instagam or email me: vintagecasiorestore@gmail.com