You need to get an SWR MEter on the radio and see if there is any output.
If you don't have a meter then you can either borrow one or get to a CB Shop and have the thing chk'd out.
To check the coax to see if it is good, you need to disconnect the coax and check it for shorting between the center conductor and the outside shield (the outer portion of the connector.
Re-chk the ***** and make sure they are in the correct locations; as 4x4RangerOffroad stated on the CB/PA ****.
To review what has happened:
There's power, there are lights on ?
The Antenna Mount it is secure and grounded ?
The Coax it is not shorted ?
The Antenna mounting stud is assembled correctly (the lock washer is not a big problem except that things may get a little loose after a while without it).
Check the SWR...
If the ***** are in the correct position, the power is on and if everything is installed correctly and nothing is shorted, the CB should work.
Why it isn't ????? you got me.
Get the CB chk;d out, first an SWR/Pwr Meter, attach it to the back of the CB and see if on the Power Setting you have any output.
IF there is no output then the CB could have a problem.
Sorry that these answers appear a little vague but there isn't a lot that can go wrong with a CB setup.
Re-chk everything get back to us.