Desktop Motherboard Ethernet Interface: Built-in Ethernet or a USB network adapter?
Pattern to record: Network performance changes while other USB devices are active.
Separate the adapter from the network
For motherboard Ethernet, separate the physical link from Windows configuration. Record the board model, link speed and switch-port behaviour; successful Wi-Fi access does not test the wired controller. USB bandwidth and power are relevant only when the active Ethernet adapter actually sits on a USB path.
Link and configuration checks
- Test a known switch and cable, inspect port magnetics and compare pre-boot and Windows detection.
- Identify the active adapter and its connection in the system, then compare a direct wired connection with the USB adapter or dock removed.
Before internal work
Lightning or surge damage can extend beyond the visible network port. Replacing a motherboard Ethernet port cannot correct an unrelated USB adapter limitation.
Verify the network path
If the checks support this cause, address the confirmed USB path if present; otherwise investigate cable, switch, driver and the built-in controller. Verification should cover cold start, negotiated speed, sustained transfer, restart and wake-on-LAN if used.
For an assessment of your desktop computer, contact AEPC in Burswood or call 027 908 8880. Provide the model and the conditions that reproduce this problem. Workshop visits are by appointment.