My out side unit has no power 24v to the contactor ,thermostat is new ,fuses breakers good ,no power to green wire on outside unit

You will have to trace the contactor wires back through any device attached and then back into the interior air handler until you find the part that is causing the problem. If the thermostat has been replaced and the problem started about that time I would look there first.

I should have mentioned I replaced the transformer also

As mentioned before you have your work cut out for yourself. Start tracing the wiring. You will eventually find the problem.

Yellow wire has 24 from thermostat,and is showing volts up to
Circuit board ,if I put 24volts to contactor system outside starts
Is crcuit board to blame