Casio GS-11 – Restoration

One day I got a message from Luke, one of my blog readers from the UK. He reached out asking if I could repair and restore his Casio GS-11 “Soccer” Game Watch. We sorted the details over email. A little while later, a small package arrived from the UK and landed on my workbench.

The GS-11 is something special. Casio released it in the 1980s as part of their Game Watch line. It’s a fully functional digital watch with a built-in soccer game. Small screen, simple controls, and a lot of fun packed into a resin case. That was Casio doing what Casio does best: taking an idea that sounds a bit mad and making it work.

Today, finding a GS-11 in good working condition is not easy. Most of them are over 40 years old. Many stopped working long ago. The ones that survived are getting more attention from collectors, and prices are starting to reflect that. It’s one of those models that casual collectors walk past and serious ones stop at.

Luke had one. It just needed someone to bring it back. 🛠️

What Did the Watch Look Like When It Arrived?

The GS-11 arrived with a dead module, a scratched acrylic crystal, and a factory adhesive between the crystal and the case that had nearly completely failed.

The first thing I always do with any watch is insert a battery and see what happens. With the GS-11, nothing happened. No display, no game, no reaction at all. The module was completely dead. That meant I couldn’t just clean it up and call it a day. There was a technical problem to solve first.

I set the module aside for a moment and looked at the case. The acrylic crystal was scratched from years of use. The kind of wear you expect on a watch that actually got worn, not one that sat in a box. The factory adhesive holding the crystal to the case had nearly given up completely. One more knock and it would have come loose on its own.

The strap was not original either. Luke also asked me to find a better match as part of the project, so that went on the list too.

Two problems to solve: one technical, one visual. Both needed attention before this watch could go back to being worn. 🔧

The Restoration Process

Step 1: Technical Diagnosis and Module Fix

The GS-11 module was dead because the metal retaining clips had too much play, preventing proper contact with the zebra strips. Bending them back into shape restored the connection and brought the module back to life.

I disassembled the watch and cleaned everything with IPA (isopropyl alcohol). After reassembly, the module still didn’t work. The problem turned out to be mechanical. Too much play between the module, the plastics, and the metal clips meant the PCB wasn’t pressing firmly enough against the zebra strips. Carefully bending the clips to create a tighter grip sorted it. A few attempts later, the module was running correctly. 😅

Step 2: Full Disassembly and Crystal Polishing

I removed the buttons from the front and lifted the acrylic crystal. The factory adhesive had almost completely let go on its own, which actually made things easier. With the crystal off and the buttons out, I had clean access to everything.

I started with the crystal. I sanded it with wet/dry paper from 1200 grit up to 7000 grit, then finished with Polywatch paste. The crystal came out clear and sharp, no trace of the old scratches. 👍

Step 3: Case Repair and Finishing

I filled the chips and surface damage on the case with super glue, then sanded everything smooth from 800 grit up to 2500 grit. To bring back the factory matte finish, I used a dry and damp white magic eraser. Keeping that matte texture is important on resin Casio cases. A shiny finish would look wrong.

Step 4: Ultrasonic Cleaning

With the case and crystal done, I put all the parts into the ultrasonic cleaner. This removed any remaining dust and polishing residue before reassembly.

Step 5: Back Cover

I polished one side of the back cover using a non-woven abrasive pad. Clean and even finish.

Step 6: Reassembly

I applied small drops of super glue to the original bonding points on the case, then seated the crystal with the buttons already correctly installed. Next came the module, a fresh coat of silicone grease on the gasket, the buzzer spring, and the case was closed.

Step 7: Strap Selection

Luke asked me to find a matching strap as part of the project. I prepared two options and sent him photos: a strap from a Casio SDB-500 and a classic strap from a Casio F-91W. Luke went with the F-91W strap. Simple, clean, and a good fit for the character of the watch. 👍

The Final Result

The GS-11 left the workbench clean, fully functional, and wearing a fresh F-91W strap. Crystal clear, case matte and even, module running correctly with the soccer game responding as it should.

It was a great project to work on. The Casio GS-11 is a proper 80s classic. A working digital watch with a built-in game, all in one small resin case. Not many of them are still alive and running. Luke’s is now one that is.

I packed it in bubble wrap and shipped it back to the UK via DHL.

Want Your Vintage Casio Restored?

This GS-11 is one example of the restorations I do. I restore vintage Casio watches for collectors around the world. You can see more of my previous projects here: 👉 casiorestore.com/projects-restorations

I work internationally and shipping is not a problem. I have already completed restorations for collectors from the UK, Sweden, Ireland, Spain, France, and more. Every project is discussed individually, so we always agree on the scope and shipping before starting. 🛠️

The process is simple:

• Write to me on Instagram: @vintage.casio.restore
• Or send me an email: vintagecasiorestore@gmail.com
• Describe the problem with your watch
• Send clear photos
• Tell me your country

If your Casio deserves a second life, I will be happy to help. 👍