Lenovo Function Board CARDPOP C (model 21JG) – spare keyboard/control board, MPN 5C50S25545

The Lenovo Function Board CARDPOP C (model 21JG) is a spare control and keyboard board designed to replace a failed or damaged front-panel module in compatible Lenovo systems. This board restores original-equipment functionality for function keys, status LEDs and front-panel controls, enabling technicians to return a device to full operational state without replacing the entire chassis or mainboard.

Advantages

This replacement function board delivers direct compatibility with supported Lenovo models, preserving factory wiring and connector layouts to ensure straightforward installation. By restoring hardware-level controls and indicator lights, it avoids software-only fixes and provides reliable physical interaction with the system. The unit is intended for part-level repairs and refurbishment workflows where original-equipment components are required.

Suitable for

• Repairing or refurbishing compatible Lenovo desktops and workstations with a faulty front-panel control board
• Replacing non-functional function keys, status LEDs or front-panel buttons
• Technicians performing component-level maintenance and parts replacement

Key specifications

• Type: spare function/control/keyboard board for front-panel integration
• Compatibility: compatible with select Lenovo devices that accept the CARDPOP C module
• Connectors: designed to match original factory connectors and cable interfaces for direct fitment
• Functions restored: function keys, front-panel control buttons and status LEDs
• Form factor: compact board intended for internal installation behind the front bezel

How to use

Power down the system and disconnect it from mains power before beginning. Remove the front bezel or access panel according to the service manual for the specific Lenovo model, taking note of retaining clips and screws. Disconnect the existing control board’s cables and carefully extract the module. Align the replacement Lenovo Function Board CARDPOP C and connect the factory cables to the original connector locations, ensuring secure seating. Reinstall the bezel or access panel, reconnect power and verify that function keys, LEDs and front-panel controls operate as expected. If any functions do not respond, recheck cable seating and consult the device service manual for model-specific diagnostic steps.

Usage recommendations

Handle the board with ESD precautions in place; use an anti-static wrist strap or mat. Use only the compatible connectors and avoid forcing cables into mismatched sockets. If uncertain about compatibility or installation, refer to the official Lenovo service documentation for your device model or consult a qualified technician.