Realtek Ethernet Adapter Driver gone after PSU swap

Troubleshooting Lost Realtek Ethernet Adapter Post-PSU Replacement: A Guide

Experiencing hardware recognition issues can be frustrating, especially after performing hardware modifications like replacing a power supply unit (PSU). If your Realtek Ethernet adapter has disappeared from Windows following a PSU swap, this comprehensive guide offers insights and troubleshooting steps to help you resolve the issue efficiently.

Understanding the Issue

In scenarios where the Realtek network adapter is no longer visible in Windows Device Manager—neither normally nor as a hidden device—it indicates that Windows may no longer detect the hardware at all. This can sometimes occur due to hardware connection issues, BIOS settings, or driver conflicts triggered or exacerbated by hardware changes.

Common Symptoms:
– The adapter was previously visible and sometimes hidden.
– After PSU replacement, the adapter entirely disappears from Device Manager.
– Attempted driver reinstallations do not restore visibility.
– Specific drivers or installers give errors, such as “Network Controller was not found.”

Potential Causes
– Hardware disconnection or loose connections during PSU swap.
– BIOS settings reset or misconfiguration.
– Hardware detection issues due to BIOS or firmware updates.
– Driver conflicts or corruption.
– Motherboard port or slot issues.

Step-by-Step Troubleshooting

Verify Hardware Connections
Power Down and Unplug: Turn off your PC and disconnect it from the power source.
Check Physical Connections: Open your case and ensure the Ethernet card is securely seated in its PCIe slot (if discrete) or verify built-in port connections.
Inspect For Damage: Look for visibly damaged ports or connectors.
Reset BIOS Settings
Clear CMOS: Reset BIOS to default settings to eliminate misconfigurations.
Restore Defaults: Use BIOS menu options or remove the CMOS battery briefly.
Re-enable LAN: Verify integrated network port settings are enabled.
BIOS and Firmware Checks
Update BIOS: Ensure you are running the latest BIOS version for your motherboard.
Load Default Settings: After updating, load optimized defaults.
Save and Exit.
Use Device Manager and Windows Diagnostics
Show Hidden Devices: In Device Manager, click View > Show Hidden Devices to see if the adapter reappears.
Scan for Hardware Changes: Right-click the root node and select “Scan for hardware changes.”
Check for Unknown Devices: Sometimes, hardware is recognized but with an error.
Install or Reinstall Network Drivers
Use Motherboard Utilities: Download the latest network drivers from Gigabyte’s official website tailored