Casio CPW-310 – Restoration

One late evening, while scrolling through eBay, I came across a tired-looking Casio CPW-310. The listing said “for parts or repair.” No photos of it working, just a scratched screen and broken lugs. Most people would skip it, but I couldn’t.

The CPW-310 has always fascinated me. It’s a 90s field watch with a digital compass, made for explorers and kids who dreamed about being one.

I looked at the pictures again, thinking, “It looks bad, but maybe it still has some life left.” So I clicked Buy Now. A small gamble, but that’s part of the fun.

A 2 weeks later, the package arrived. I opened the box, and there it was, faded, scratched, and worn out. But in that moment, I knew this watch had a story worth restoring. 🛠️⌚

What was the condition of the watch at the start?

When the Casio CPW-310 arrived, it looked far worse than I expected. The first thing I noticed was that two lugs were broken, which meant it couldn’t hold a strap at all. The crystal was full of scratches, and the once-gray case had turned pale and uneven from years of wear.

The LCD screen looked strange, with a strong orange tint that didn’t belong there. The printed text around the bezel and buttons was almost invisible, completely faded from use.

I opened the caseback to check the module, and that’s when the real horror appeared. Inside, I found two corroded silver oxide batteries, covered in brown and orange residue. The whole area was sticky and rusted, like the batteries had leaked years ago.

For a moment, I thought this one might be a total loss. But then again, that’s what makes these restorations exciting. When a Casio looks beyond saving, it becomes the perfect project. 🔧

Restoration Process: Bringing the CPW-310 back to life

1. Disassembly and cleaning the module

I started by carefully opening the watch and removing the entire module. The corroded batteries were stuck to the plastic holder, so I had to work slowly with tweezers. Both cells had leaked badly. They were almost fused together.

Once they were out, I cleaned every part with isopropyl alcohol (IPA) using cotton swabs and a soft brush. It took time to remove all the orange and brown corrosion. After cleaning, I left the parts to dry and checked all contacts under a magnifier to make sure no metal parts were damaged.

2. Fixing the LCD and replacing the polarizing film

The display was badly discolored, so I decided to replace the polarizing film. Removing the old one was difficult because it had melted slightly into the LCD over time. I used a thin plastic tool and a lot of patience. One wrong move could have cracked the screen.

After several careful attempts, the old film finally came off. I cleaned the glass again and installed a new polarizing layer, adjusting its angle until the contrast looked perfect. The screen turned clear again, just like it should be.

3. Reassembling and first power-up

With everything cleaned and ready, I reassembled the module and installed fresh batteries. For a few seconds, nothing happened. Then the digits appeared. The CPW-310 came back to life. The moment when a “dead” Casio starts working again is always pure joy.

4. Restoring the case and crystal

Next, I moved to the case. I cleaned it with mild detergent and warm water to remove old dirt. Then I began wet-sanding the resin using paper from 1200 to 7000 grit. I finished with Polywatch to bring back the shine on the crystal.

To get a more original matte look, I used a white magic sponge to tone down the polish slightly. The case looked fresh again but still kept that factory texture.

5. Repairing the broken lugs

Both lugs were missing pieces. I used baking soda and super glue to rebuild them, applying thin layers and shaping them with a file once dry. After that, I painted them gray so they matched the case color. The repair was nearly invisible and strong enough to hold the strap.

6. Restoring the text and details

I filled the engraved markings with new paint using a fine brush. The letters around the bezel finally became visible again, restoring the original look of the CPW-310.

7. Final assembly

Finally, I installed a new original strap made for this model. I checked all functions — timekeeping, alarm, backlight, and compass. Everything worked perfectly.

The restoration was complete. The old field watch that once looked like scrap was now ready for another adventure. 👍⌚

Final Result

After hours of careful work, the Casio CPW-310 looked nothing like the watch that arrived in the mail. The display was crisp, the digits bright, and the strange orange tint was gone. The case regained its proper gray tone, clean and even, with a soft matte finish that felt just right.

The repaired lugs were solid and blended perfectly with the case. Fresh paint filled the engraved markings, bringing back the classic CPW-310 look collectors know. I finished it off with a new original strap, and suddenly it looked ready for another decade of use.

All functions worked, time, alarms, compass, and backlight. Seeing it alive again was pure satisfaction. What started as a risky eBay buy turned into one of my favorite restorations. Another forgotten Casio saved from the parts bin.

If you have an old Casio that needs the same treatment, I can restore it for you.
📧 Contact me: vintagecasiorestore@gmail.com
📸 Instagram: @vintage.casio.restore