I have more information about that machine:
Is a NCR mobo model 745X-35XX

The mother has a very big card plugged in a very big slot and this big card has the 2 PCI and 2 ISA expansion slots, a CR2032 battery that feeds the BIOS, and the on-board Phoenix BIOS, in the motherborad is the on-board video hardware (with a VGA interface and a LCD interface), the on-board LAN port (it doens't appear to work), two on-board Serial Ports, the two on-board PS/2 for keyboard and mouse and another CR2032 battery (why another battery? What is feeding?).

The on-board LAN port is not working, Can be this brown socket the BIOS of that LAN port? or is another socket for another main BIOS?