Since you described that the board has isolation transformers, I would assume that they followed the spec and put in network jacks with magnetics <http://electronics.stackexchange.com/questions/27756/why-are-ethernet-rj45-sockets-magnetically-coupled> instead of direct connections. As I understand it, there are two types of magnetics - those built into the jack (as seen in this Raspberry Pi blog post <https://www.raspberrypi.org/blog/manufacturing-hiccup/> with X-Ray images), and those which use a separate chip or transformer.
I believe you are correct that the only way to get it working would be to desolder the fried transformer and replace it with a new one. Depending on your soldering skills and comfort level, you could likely replace the fried part with a new one. Unfortunately, the only people I know who have done this successfully have been working with the type that has integrated isolation components (like the RasPi), not the type that has separate ones. Assuming the chips are through-hole (like most jacks are), it should be exactly the same difficulty as replacing the jack itself. Otherwise, you might have a hard time. It's hard to know for sure without looking at the board directly. Moshe -- Moshe Katz -- mo...@ymkatz.net -- +1(301)867-3732 On Mon, Jul 25, 2016 at 5:41 PM, Karl Fife <karlf...@gmail.com> wrote: > The 6th Ethernet port (em5) on my Lanner fw-7541D died Saturday night > during the electrical storm. Just the one port. > > Apparently fried, apparently by an electrical anomaly. > > Now, the link light is always on (dimly lit), whether populated or not, > and neither the POST, nor the OS detects the presence of the fifth port. > > Interesting how it failed: The fried port 'simply' broke connectivity for > the interface's LAN segment. Everything else continued to work. I kinda > didn't believe the report that Internet was out for the one LAN, since the > other was not. After some testing, I found the system would not come up > after reboot because it had gone into port reassignment mode since the > config made reference to a non-existent interface. > > I edited the config in VI to de-reference the interface, and All's well. > > I really like this Lanner hardware, and would like to keep it in service. > Ideally I'd like to fix the (now dead) spare port so that I still have a > spare. > > Can anyone tell me what's component is typically fried in this scenario? > Is it the NIC controller chip itself? I'm guessing it's not, rather I'm > guessing it's just the big, blocky Ethernet Isolation transformer/amplifier > that's been fried. I'm also guessing that the reason the system is still > functional (at all) is because the little dude did its job. I know it's a > long shot, but I'd like to hear if anyone has ever repaired a fried > Ethernet port on a motherboard. > > Also ironic, everything's very well grounded with a dedicated earth-ground > via #6 AWG except the one (damned) switch that services that one (damned) > LAN. I imagine if I'd gone to the trouble of running a dedicated ground to > that switch, it may not have sunk the spike. Any experience or war stories > in this arena appreciated as well. Memo to myself: Run fiber to switches > on different power/earth. > > -Karl > _______________________________________________ > pfSense mailing list > https://lists.pfsense.org/mailman/listinfo/list > Support the project with Gold! https://pfsense.org/gold > _______________________________________________ pfSense mailing list https://lists.pfsense.org/mailman/listinfo/list Support the project with Gold! https://pfsense.org/gold
