Craig,
Welcome to TFP... A great place to find the answers to all of your "Indirect" questions..
About a year or so ago, my neighbor's house took a direct lightning strike and we got what was left over...
The Pentair tech came out and replaced the main circuit card, salt cell power supply card, and the ScreenLogic Protocol adapter and we were back up and running. Other than the enclosure, relays, and transformers, that is about the whole system.
If you are talking about replacing individual components, such as resistor, IC chips, etc... that is just not done anymore. From a maintenance company's point of view, it costs more than it is worth. All that is done now, is the replacement of sub-assemblies, such as the Main Board...
There are places that can troubleshoot and repair your main board and then send it back to you. The only problem is how many other things did the lightning take out, if anything?
Most likely the com port was taken out on your main board. When that happens, nothing on the communications port will work.
I suspect the tech just put your system in the Service mode to get you pump running. Go out and look at the pump's display and see if it shows the RPM etc, or it if shows "Display Not Active"...
Tell us more about your equipment.. What kind of pump, SWCG, remotes, do you have??
Thanks,
Jim R.