Casio JP-100W (Blue) – Restoration

Introduction

The Casio JP-100W Pulse is one of those 1990s experiments that feels both futuristic and nostalgic at the same time. Released in the mid-90s, it featured a built-in pulse sensor, letting you measure your heart rate directly from the watch — a wild idea years before smartwatches made it common.

This particular JP-100W has a story. Back in 1995, someone bought it in Grenoble, France. Along with the watch came the original receipt and manual, which makes it a complete time capsule. Even better, this one is the blue version, far less common than the standard yellow.

By the time it reached me, the watch had seen decades of use. The case was scratched and cracked, the glass dulled, and the whole thing looked beaten down. But because the pulse sensor was still functional, I knew it had real potential. Restoring it felt like a way to bring both the design and its history back to life.

In this post, I’ll walk through the restoration process — from repairing the cracked case to polishing the glass — and show how this rare blue JP-100W returned to working, wearable condition after nearly 30 years.

What was the condition of the watch at the start?

When the Casio JP-100W (Blue) arrived, it carried every scar of its 1990s life. The acrylic glass was scratched, making the display look cloudy. The resin case had a deep crack on the side, the kind that makes you wonder if the watch can even be saved.

The surface was beaten and worn, showing years of everyday use without much care. Surprisingly, the pulse sensor worked perfectly, which is rare for a watch of this age. That single detail gave me confidence it was worth the effort.

The watch came with its original paperwork — purchase receipt and manual from 1995. Having those alongside the worn watch made the project feel less like fixing plastic and more like reviving a piece of history.

👉 Collector’s note: The blue JP-100W is much harder to find than the standard yellow version. Add in the original paperwork, and it becomes a complete collectible, even before restoration.

How did I restore the Casio JP-100W (Blue)?

Step 1: Polishing the glass

The acrylic glass was scratched and cloudy. I carefully sanded it down with fine sandpaper, then polished until it regained full clarity. A clean crystal immediately made the display sharper and easier to enjoy.

Step 2: Repairing the cracked case

The side of the case had a deep structural crack. To fix it, I used a piece of plastic tie wrap as reinforcement. I melted it into place with a soldering iron, bonding it with the case. After that, I sanded the area smooth so the repair blended with the rest of the resin. This step turned a weak spot into a solid fix.

Step 3: Cleaning and refreshing the case

Once the crack was repaired, I cleaned the entire case, removing dirt and small scratches. The blue resin looked brighter again, and the edges regained their sharp shape.

Step 4: Testing the pulse sensor

The highlight of this model is the pulse sensor. Luckily, it worked perfectly from the beginning. I tested it after cleaning to make sure nothing was damaged during the restoration.

Step 5: Strap replacement

The original strap was gone, so I added a fresh replacement that fit the case style. This made the watch wearable again while keeping it close to the original look.

👉 Restorer’s tip: Case crack repairs on vintage Casios need patience. Heat can damage resin if applied too quickly, so it’s better to use short controlled touches with the soldering iron and sand carefully afterward.

Final Result

After hours of careful work, the Casio JP-100W (Blue) finally looked the way it deserved. The glass is polished clear, the cracked case repaired and smooth, and the blue resin bright again. Most importantly, the pulse sensor works perfectly, proving that Casio’s 1990s health experiment still holds up nearly 30 years later.

With a new strap attached, the watch is not just functional but fully wearable. Paired with the original receipt and manual from 1995, it feels like holding a complete time capsule from the mid-90s.

For me, restoring this JP-100W wasn’t just about fixing scratches. It was about giving new life to a watch with both technical charm and personal history. ⌚✨

Now I’d love to hear from you. Have you ever restored a Casio pulse watch, like the JP-100W or JP-200W? How do you approach cracked resin repairs, and what tricks worked for you? Share your experiences, tips, or before/after photos — it’s always inspiring to see how other collectors keep these quirky models alive.