A stable power distribution system is the foundation of any arcade cabinet. On machines like Slam A Winner , HockeyZoo , and Hole in One , power supply voltage fluctuations or ground faults can mimic broken optical sensors, corrupted logic board ICs, or motor failures. Arcade cabinets typically use a standard Switching Power Supply (SPS) providing regulated DC outputs. Understanding how to measure and adjust these voltage rails is critical before replacing mainboards or peripheral sensors. 1. Key Voltage Rails & Their Functions Arcade switching power supplies deliver specific DC voltage rails to power different hardware modules: Voltage Rail Target Operating Range Primary Arcade Components Powered Symptoms of Failure / Out-of-Spec Rail $+5\text{V\ DC}$ $4.85\text{V}$ – $5.20\text{V}$ Mainboard CPU, RAM, Logic ICs (e.g., 74HC245), TTL optical sensors, LED displays Low: Random game resets, frozen displays, unread sensors. High: Overheated IC chips, permanent CPU damage. $+1...