Pattern to record: Brief movement causes link loss despite an otherwise good cable.

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. One possible explanation is that a broken latch or side load keeps the plug from maintaining contact.

Link and configuration checks

1. Test a known switch and cable, inspect port magnetics and compare pre-boot and Windows detection.
2. Inspect plug retention and port shell alignment under gentle handling.

Before internal work

Lightning or surge damage can extend beyond the visible network port. Taping a loaded cable can transfer force into motherboard solder joints.

Verify the network path

If the checks support this cause, replace the cable and repair a loose port before further use. 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.