Spike kills DH+ port - anyone fixed them?

I have a bunch of PLC5/20 that all have had their DH+ ports damaged by distant lightning strikes at a remote station. Each time the PLC continues to work fine but wont communicate over DH+. Eventually we will find a surge suppressor or isolator that can prevent this but until then ...

Has anyone taken the time to fix this problem? I am about to open one up and begin that quest ( my background is bench tech for depot repair of diagnostic equipment) but if anyone already knows the chip and where to get replacements, I would love to know about it.

See link for surge protection for your DH+ network.

http://www.lashen.com/vendors/leviton/spd-network.asp

I have one on both ends already, it did protect the other one of the pair and that's not nothing, but it still is annoying.