Ethernet Card/logic Board Issue


A recent electrical storm did in my speedstreem 5100 modem (sbcglobal DSL).
I have a new modem but the mac G4 tower will not respond. Ethernet light on modem does not come on. SBC tech help indicated that it was likely a ethernet card problem.
I have subsequently found out that apparently the ethernet card is not independent of the logic board and most likely will need replacement. My question is : Is there anything that I can do short of replacement / service to resurrect my ethernet? If logic board needs replacement can it be done for under $500.00? I'm feelin kinda sick and am acutely aware of the merits of surge protection. I am not a techie but I can follow directions fairly well in other words you should "dummy-up" your response for me so I am sure to grasp. Thank you in advance for your consideration of my issue. I hope I have given you enough info. Machine is out of warranty.
Try resetting your PRAM and NVRAM -- this may or may not help restore the ethernet ports.

Reset PRAM: hold down Command-Option-P-R immediately after booting your Mac and keep them held down until the Mac restarts 3 times.

Reset NVRAM: hold down Command-Option-O-F immediately after booting your Mac and keep them held down until you get a screen of text with a command prompt. Type "reset-nvram" (without the quotes) and press enter, then type "reset-all" (without the quotes) and press enter.

If those don't work, more troubleshooting will be needed... it's impossible to say whether they're dead or not at this point.
Thanks for your input! I read a little on APPLE help which said that after OS10 the PRAM no longer involves the network functions. Do you still think it would be a good idea to reset them anyway?
If onboard ethernet is fried, go for D-Link or any Mac compatible PCI Ethernet (base 100/1000) card. You'll have to configure your "Network" panel.