The HALO TG110-S055N2RL part is available from Future Electronics for $4.70 each,
http://www.futureelectronics.com, order online and have it a week later. Prior to voiding the warrantee by opening the case I suggest contacting FIRST to see if they will replace under warrantee. Based on what I saw on one of our damaged units (both ports) the HALO isolation transformers are getting damaged as the signal activity on either side of the 1:1 transformer is different. It is unclear whether the damage propagates beyond the HALO part to the Davidcom chip, but things looked promising at the Davidcom to HALO interfaces.
In the case of no waranntee replacement, I would spend the $5 or $10 to try the repair and then have a non-competition DS (better than a paperweight

). The part is 16 lead Surface Mount and can be replaced by someone with a little skill who is careful not to lift the copper pads.
We implemented a practice of always connecting a wire with series 1 MOhm resistor between the cRio case and the DS case prior to connecting the Ethernet line. The wire connection is maintained at all times during tethered operation and removed only after the Ethernet cable is unplugged. Prior to this we blew 3 DS Ethernet ports, since none.