If you all recall, I had one zone that would not put out enough
pressure/volume to pop-up the heads and the water just dribbled from all
heads. Finally through in the towel and called a sprinkler repair
service. His first comment was that he would have it fixed in about 15
minutes. 2 hours later - after trying new diaphragm, checking for leaks
in underground lines, cleaning the antiback flow valve found a partially
plugged barb fitting at the valve box. Sure glad I didn't drive myself
any more crazy than already am. Well worth $$$ to let someone with
experience sort this out.

Thanks for all the suggestions and I did try them all before going to
the pros.