I have PS4, Im level 79 , and At the Castle the NPC radio guy wont sit down, just repeats ,"You need to fix The Transmitter so I can Broadcast. Ive done everything in my power for hours on end, even seen someone say I had to reach level 9 intelligence to get a fix, Which I now have, Still no fix. Please help. I know tgeres a fix for PC, I have PS4. Thank you very much.

Yeah, your bug is on the wiki. Quote: "The Minuteman in charge of broadcasting Radio Freedom may complain that the transmitter is not being powered despite having power, usually after starting the Old Guns quest. This is accordingly due to the Minuteman becoming hostile to Sarge in the Castle tunnels and so should be able to be prevented by eliminating Sarge before Old Guns. Otherwise, this prevents use of Radio Freedom."

Sounds like the only option for you, since you're on console, is to simply load an earlier save.

*edit* There's also this http://fallout.wikia.com/wiki/Radio_Freedom#Bugs

Have you tried building a generator and hooking it up to the transmitter?

Yes , it was already built.I believe mine started because some person started shooting at me at the Castle!! Im way too far to go back (level 79) Ive been reading more and more about this particular bug and I guess we have to wait for a patch. Seems like Bethesda is ignoring everyone whos complaing about this for consoles.