Member Avatar for gc_don

If i use the pc without lan, it works fine no problem at all. But the moment i connect the pc on LAN, it shuts down. Using cross cable i can connect it to another desktop. But not possible to connect to LAN using straight cable.
Tried changing port and cable but no use??

OS - WIn XP

  • 5 Contributors
  • 9 Replies
  • 213 Views
  • 3 Days Discussion Span
  • Latest Post Latest Post by Nauman Badiwale

Dani AI

Generated

Brief expert summary and focused tests

The facts in the thread point away from antivirus or a simple driver problem and toward an electrical/PHY-level issue with the on‑board NIC. Because a direct cross‑cable link to another PC works but plugging the same port into the LAN causes an immediate shutdown, the most likely causes are: the switch/router port is supplying power (PoE) or there is a grounding/short between the NIC chassis and the network device. ’s PSU suggestion and ’s Wake‑on‑LAN tip are sensible to check, but they do not fully explain the very different behaviour when the NIC is connected to the wider LAN.

Troubleshooting steps (in order)

  • Reproduce and describe exactly what happens: does Windows start a shutdown sequence, or does the machine instantly lose power? If it is instant, treat it as a hardware/short/overcurrent event.
  • Try a different network device/port that you know is non‑PoE (home router, a different unmanaged switch or a laptop). If the shutdown only happens with the original LAN device, suspect PoE or a faulty switch port.
  • Power‑off test: turn the PC off, plug the LAN cable into the on‑board NIC, then power the PC on. If it boots fine, the failure is triggered by hot‑plug insertion rather than link negotiation.
  • Disable Wake‑on‑LAN in BIOS and in Device Manager power settings (as suggested).
  • Inspect the on‑board RJ45 for bent pins, corrosion or a damaged shield; try an unshielded Cat5e/6 patch cable to rule out shielded-ground loops.
  • Check Windows Event Viewer (System) for Kernel‑Power events and enable write‑memory‑dump / disable auto‑restart to capture driver or kernel faults.

If these tests show the on‑board NIC is at fault, leave it disabled and use the working PCI (or USB) NIC. If a PoE or switch fault is discovered, have the network gear checked/replaced. If the on‑board port shorts to chassis even with a non‑PoE device, the motherboard NIC hardware should be repaired or the board replaced.

Recommended Answers

All 9 Replies

Member Avatar for Rik_

Is it a pci lan card or is it built in?

Member Avatar for Perminder

Check your antivirus. Remove your antivirus and then connect to lan. I think it will solve your problem

Member Avatar for gc_don

Is it a pci lan card or is it built in?

It is built in lan.

Member Avatar for gc_don

Check your antivirus. Remove your antivirus and then connect to lan. I think it will solve your problem

Formatted the PC, installed only LAN driver, still same problem. The moment I connect lan cable, pc shuts down.

Member Avatar for Rik_

2 things I can think of, either your built in lan is faulty or your PSU isn't up to the task.

Have a look at the label on your PSU and let us know make, model, wattage, and amps on the 12volt rail.

Member Avatar for gc_don

2 things I can think of, either your built in lan is faulty or your PSU isn't up to the task.

Have a look at the label on your PSU and let us know make, model, wattage, and amps on the 12volt rail.

Built in lan is not faulty, coz i can access other PC using cross cable.
Now i've installed another card and it's working fine. And disabled the inbuilt one. But one more thing, If i enable the inbuilt one and plug in the cable in inbuilt lan, same thing happens.

well
Thank you every one for your efforts.

Member Avatar for Rik_

Only thing I can suggest is to have a look on your mob makers site and see if there is a more up to date driver.

Member Avatar for Salem

Perhaps you've got Wake on LAN with the bits reversed (so it's shutdown on LAN) ;)

Joke aside, check whether such a feature is enabled in the BIOS (or in Windows for that matter).

Member Avatar for Nauman Badiwale

reinstall ur lan card drivers and are u directly connecting two pc or connecting through an access device like switch or hub.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.