Lightening damage - any hope?

Most of the more valuable components should be able to be repaired. Keep in mind repair charges usually start at a few hundred $$, so some stuff might not be worth it. As others have said, do some basic diagnosis if you have not done that. Check for fuses and basics. If you are able to use a multimeter you can sometimes figure out where the current stops flowing. If the damage came through the network cable, might be a more difficult thing to diag, and we have had that happen in the past few years ourselves. I still have a HT receiver that no longer connects to the LAN due to storm damage. That said, most of my gear is behind a protection device that also protects the LAN connections. Internet gateway is on a separate UPS/surge protector. Lifetime Florida resident here, and have spent thousands at the repair shop in my life due to storms, and now my protection devices probably cost more than my first stereo rig! :-) Lessons learned the hard way.

Some units may also have internal fuses in addition to the Aac mains.   Might be worth taking the covers off what you can. 

Thanks for the comments and ideas. BTW, I do have everything powered thru a Furman power conditioner. And I checked the ground wire at the outside cable connection and it is as it should be. I bought additional media converters to isolate the Ethernet on my replacement/repaired gear that wasn't isolated. 

I found the fuse on the power supply of the Sony Blu-ray player and it is fine, but the service manual provided instructions to check 2 pins that connect the PS board to the main board for +12v and they both showed nuttin'. So, at least the PS board got zapped and possible more. I haven't a clue on how to repair the PS board and a replacement is $100. The player was only $500 and there they be more trouble if a new PS energizes the other boards and they don't work. Unless someone has a way to test the components on the PS board I guess I'll sell the unit for parts and get something else.

The Marantz is another can of worms. There are a number of boards stuffed on top of the main board and PS board such that disassembly will be quite a task. I think I'll take it to my excellent local repair shop and pay for a diagnosis.

Thanks again everyone.

Are you sure it was Ethernet issue and not power mains spike? It is pretty common for storms to cause voltage spikes. This is why I have surge protection for the entire home.

Now, have you checked fuses? They may have been blown.

None of the damaged items have 'regular 'fuses like an amp has. I suspect they are mounted on the circuit boards. Any hints on what to look for on the boards to identify a mounted fuse?

The damaged items are probably not worth repairing, but I'm taking this 'opportunity' to learn a little more about them.

Thanks for the help.