Mk 52 keyboard

MK-52 Keyboard PCB Replacement

This repository contains a custom PCB design intended to replace the original, non-repairable keyboard board of the Soviet calculator Elektronika MK-52.

The board was designed and routed in KiCad as a personal project to restore my own calculator. I decided to publish the design files in case they are useful to other MK-52 owners facing similar keyboard failures.

---

Background

The original keyboard assembly of the Elektronika MK-52 is difficult or impossible to repair once the membrane or contact layers degrade. Since original spare parts are no longer available, creating a replacement PCB becomes a practical restoration approach.

This project provides:

• A reverse-engineered keyboard PCB layout
• A modern, manufacturable replacement board
• KiCad project files for modification or adaptation

---

Project Status

This is a hobbyist restoration project created for personal use.
It is not an officially supported product and is not affiliated with the original manufacturer.

The design was tested on my own calculator, but hardware variations, component tolerances, and assembly differences may affect compatibility.

---

Repository Contents

• KiCad project files (.kicad_pro, .kicad_pcb, .kicad_sch)
• Schematic files
• PCB layout files
• Production-ready Gerber files (in gerber/)
• 3D model of the tactile button (.step)

---

Manufacturing

The gerber/ directory contains all files needed to order the PCB from a manufacturer (e.g., JLCPCB, PCBWay, OSHPark). The board is a standard two-layer design.

---

Tools Used

• KiCad (PCB design and routing)

---

Disclaimer

This project is provided as-is, without any warranties of any kind.

• It is an amateur project.
• There is no guarantee that it will work in your specific device.
• Manufacturing and installing this PCB requires electronics experience.
• Any attempt to disassemble or repair your calculator may result in permanent damage.
• You assume full responsibility for any damage caused during repair or modification.

If you are not confident in your repair skills, consider consulting an experienced electronics technician.

---

Why This Exists

The Elektronika MK-52 is an iconic programmable calculator, and many units are still functional except for keyboard failures. This project exists to help preserve and restore these devices instead of letting them become unusable due to a single non-repairable component.

---

License

CERN Open Hardware Licence Version 2 - Permissive

---

If this project helped you restore your MK-52, feel free to share your results or improvements.