Lost Network Connection

Sorry for the weak info…Power supply fried in a P4 with XP Pro. Replaced with P4 400 watt power supply. System claims all components working properly. Lost Network Connection. Disabled onboard LAN and installed PCI. Connection light verifies connectivity but can’t communicate with printer using TCI/IP port. Tried restore and ping. NADA. All TCP/IP set up acurately. Motherboard fried? No tools or loopback to test. Serious help needed. Thanks!!!