Royal 660-9 Coca-Cola Vending Machine

Problem

The Royal 660-9 uses aging, machine-specific controller and vend-position hardware. When these assemblies fail, blind parts replacement is expensive and some original components are difficult to source.

Description

What I built or investigated

I documented my own Coca-Cola machine, inspected its controller electronics, examined a suspect surface-mount area, traced the L298N-based motor-drive section, and studied the optical rotary feedback assembly that tells the controller where the vend mechanism is positioned.

Iterations

The work did not happen in one jump.

1. 01

   Documented the personally owned Royal 660-9 machine and its existing control hardware.

2. 02

   Opened the controller and inspected a suspect surface-mount area for physical damage or a failed component.

3. 03

   Identified the L298N motor driver, surrounding logic ICs, heat sinking, and related drive circuitry.

4. 04

   Examined the optical rotary position-feedback wheel used by the vend mechanism.

5. 05

   Separated the overall machine restoration from the dedicated encoder-replacement subproject so each problem could be tested independently.

6. 06

   Continued building a machine-specific evidence base instead of treating unrelated customer equipment as the same project.

Result

Where the project landed

A correctly documented restoration platform with the machine, controller board, motor-driver stage, and optical feedback hardware tied to one verified Royal 660-9 project. The machine remains an active repair and reverse-engineering effort.

Lessons

What carried forward

• Machine identity and image provenance must be established before technical conclusions are attached to photos.
• Controller drive circuitry and position feedback are separate systems even when they work together during a vend.
• Obsolete equipment becomes repairable when the system is divided into documented functional blocks.

Images & evidence

Work in context