Electromagnetic interference (EMI) can cause significant problems for arcade machines, resulting in screen flickering, audio static, random resets, and interference with nearby electronics. Fortunately, there are several effective methods to mitigate these issues and ensure stable operation.

1. Proper Grounding and Bonding

Establishing a solid grounding system is the first defense against EMI. Ensure the arcade cabinet has a proper earth ground connection through the power cord. All internal metal components should be bonded to this common ground point to prevent ground loops, which can act as antennas for EMI. Use star-point grounding where practical to create a single reference point.

2. Strategic Shielding

Apply EMI shielding to sensitive components and cables. Critical boards like the PCB, power supply, and video output circuits can be housed in metal enclosures or treated with conductive coatings. Shielded cables are essential for video connections and power wiring – look for cables with braided copper shielding and ensure the shield is properly grounded at one end.

3. Install EMI Filters

Add ferrite cores to power cables and video wires. These inexpensive components suppress high-frequency noise by adding impedance to unwanted signals. For more severe cases, install inline EMI filters on the power input side of the machine. These filters typically combine capacitors and inductors to block interference from both entering and leaving the cabinet.

4. Component Separation and Orientation

Physically separate noise-generating components from sensitive ones. Keep power supplies and transformers away from audio and video circuits. When this isn't possible, orient boards so that their sensitive components face away from interference sources. This simple spatial arrangement can significantly reduce coupling between components.

5. Quality Power Conditioning

Use a dedicated line conditioner or isolation transformer for your arcade machine. These devices clean incoming power by suppressing surges, spikes, and noise while providing stable voltage output. This is particularly important in locations with unstable power or numerous electronic devices sharing circuits.

Regular maintenance including checking ground connections, inspecting cables for damage, and cleaning dust buildup also contributes to reducing EMI over time. Implementing these strategies will not only improve your machine's performance but also ensure compliance with FCC regulations regarding electromagnetic emissions.