When it comes to repairing classic arcade machines, having the right diagnostic tools is crucial for efficiently identifying and fixing issues. The most common tools used by technicians include multimeters, logic probes, test ROMs, oscilloscopes, and dedicated test equipment.

A multimeter is indispensable for checking voltages, continuity, and resistance on PCBs and power supplies. It helps verify if components are receiving correct power and detects shorts or open circuits. Logic probes are used to test digital logic states on chips, indicating high, low, or pulsing signals—vital for diagnosing CPU and RAM issues. Test ROMs replace the game software to run hardware checks, displaying error codes for faulty components like video RAM or input ports. Oscilloscopes visualize electrical signals, allowing technicians to analyze waveforms and timing problems in analog circuits or monitor clock signals. For specific systems, dedicated testers exist for joysticks, monitors, and power supplies.

Combining these tools enables a systematic approach: start with power supply checks using a multimeter, then proceed to logic probing and test ROMs for board-level faults. Oscilloscopes add depth for complex signal analysis. Mastering these tools is key to successful arcade machine troubleshooting and preservation.