Mesa 7i96s / Network no longer working

It does sound like something on the mill is causing major EMI of perhaps ESD

Ethernet is transformer isolated and the 7I96S has ESD protection on the
7I96S side of the transformer so should be fairly well protected from surges.

Large ESD (static) discharges can cause damage however. Protection from
static damage is improved if the 7I96S frame ground pin is connected to earth
ground.

Hi.

Did You have any luck fixing the card. I have the same exact problem.

If you unplug the Ethernet cable from the 7I96S, do any lights on the RJ45 connector illuminate?
If so, this indicates ESD damage to the 7I96S's Ethernet port. This can only be repaired by replacing
the Ethernet chip.

To avoid this kind of damage, it important to ground the chassis ground on the 7I96S to earth ground.