Ethernet strange issues - what's the reason?

[Flatko]

Hi there,
I bought an old second-hand HP dv6 laptop and it has a strange issue - the ethernet card (NVIDIA MCP65) appears as working, but in fact it doesn't work. When I plug an ethernet cable, the LED lights up and the OS says there is a link - it detects that a device has been plugged on at the other end. The DHCP client starts searching and the corresponding LED starts blinking, but it never manages to establish connection. It happens just the same in Ubuntu and Windows, so it coundn't be a software problem. I tried changing speed to 10Mb/S, but still no result. The router itself is working, I tried it with another PC.
I recently opened the laptop for internal cleaning and saw that one connector on the mobo (to the power block) is slightly burned. On the other hand, the laptop wasn't cleaned for years, so it was heating up a lot.
Could a lower voltage lead to this strange behavior (there are no voltage sensors in BIOS), or the chip is rather fried before cleaning the laptop? Is there a way to diagnose it and tell for sure where is the problem and is there a way to solve it?

 

[webworkings]

Have you tried rebooting the modem and then try loading it on the computer, when fully rebooted?

Although it works with other devices, this could be the cause. It is a common problem/solution.

If it isn't that, then there are a few diagnostic programs online that can test the connection and search for possible conflicts.