[SOLVED] Network card problem

Jun 20, 2021
I used to connect the ethernet cable directly to the motherboard, but then the back of the motherboard touched the case and when I plugged in the cable it shocked both the mobo and the modem.

The modem continued working and the short stopped at the LANGuard, so I had the mobo repaired and installed a network card. It worked fine for about a week, then the ethernet stopped working so I tried using a different network card and when I connected the cable the card got fried.

A bit after that the modem literally started smoking so I've replaced it, now I'm wondering if the modem is what fried the network card and I can just use the other one I have now.
In general ethernet ports are isolated from everything else...mostly to avoid interference but it also prevent power issues. When some equipment is damaged say by a lighting strike or a large power surge it can cause all kinds of shorts and other problems that will defeat the isolation. You have to hope the modem did not damage the new ethernet ports.