Disassembling the KVM switcher

Disassembling a KVM switch involves removing the case screws, separating the metal housing, and inspecting the internal PCBs for HDMI, USB, and control chips.

General Disassembly Steps

1. Power Off and Disconnect Ensure the KVM switch is unplugged from all computers, monitors, and power sources to prevent electrical hazards.
2. Remove Case Screws Most KVM switches use Phillips screws to secure the metal or plastic casing. For example, the Monoprice Blackbird 4K HDMI 2.0 KVM uses a Phillips #1 bit to remove four screws, allowing the case to be separated into front/sides and back/top/bottom pieces ( ).
3. Separate the Housing Slide or lift the top and bottom panels off carefully. Some models have the front panel attached to the PCB, so avoid forcing the case to prevent damage ( ).

Internal Components

• HDMI/Video Switching HDMI signals are typically routed through dedicated multiplexer chips. For instance, generic HDMI KVMs use IT66341TE chips for 4-to-1 HDMI muxing and IT66321E for switching between streams ( ). High-end models like TESmart HDC202-X24 maintain Ethernet and audio links with separate chips to preserve connectivity during switching ( ).
• USB and Keyboard/Mouse Control USB ports are managed by microcontrollers or ASICs, such as the CH559L, which monitors key codes for input switching ( ). PS/2 ports, if present, are usually directly connected to the main PCB ( ).
• Audio and Ethernet Some KVMs include audio and Ethernet chips that remain connected to PCs even when switching, allowing instant restoration of mic, speaker, and network functionality ( ).
• Microcontrollers Many KVMs use an 8-bit microcontroller to coordinate input switching and manage peripheral signals ( ).

Additional Notes

• Debugging and Repair Some KVMs include UART headers, bootloader outputs, and debug jumpers for firmware updates or diagnostics ( ).
• Caution Avoid touching exposed circuitry or connectors to prevent static damage. Keep track of screws and small components during disassembly. By following these steps and understanding the internal layout, you can safely disassemble a KVM switch for inspection, repair, or educational purposes while identifying key components like HDMI muxes, USB controllers, and microcontrollers.