Do you have power coming back from your thermostat when the unit is
calling for air? I would check for voltage at the stat and from the
stat first. If you have an electronic stat you could have blown the
stat board. Do you have heat?

Yes I do have heat because I already replaced the transformer on the
furnace that I also have blown.
Yes, I do have voltage on the thermostat.
From the attic unit (fan) there is 24V going to the thermostat. 3
wires white, red and green connecting to RC, G and Y on the
thermostat. There are 24V on the thermostat.
2 wires 24V go to the condensing unit. I do have the 24V on the
condensing unit at the end of the wire, but I can't find the voltage
on the electronic board or any other wire on the condensing unit as I
described in the first message opening this discussion.
I appreciate all your help but most of what you say sounds Chinese to
me. Is there an easy way I can test what's wrong with my condensing
unit? Can someone say with high confidence that it's the electronic
board could have blown ?

Thanks,
Jack